[{"data":1,"prerenderedAt":782},["ShallowReactive",2],{"blog-post-superposition-sequencer":3,"sibling-dives-superposition-sequencer":780,"learn-track-superposition-sequencer":781},{"id":4,"title":5,"authors":6,"body":8,"breadcrumb":706,"builders":710,"byline":727,"challenge":732,"courseAuthor":732,"courseLead":732,"dek":733,"description":734,"draft":735,"extension":736,"eyebrow":737,"featured":735,"finish":732,"fork":738,"hero":740,"heroAlt":732,"heroCta":732,"heroImage":732,"homepageFeatured":735,"kind":742,"lessonCount":732,"meta":743,"navigation":157,"newsItems":732,"next":732,"ogImage":744,"order":732,"outcomes":732,"path":745,"publishDate":746,"readingTime":747,"related":748,"relatedProjects":749,"seo":771,"stem":774,"tags":775,"track":732,"trackName":732,"__hash__":779},"blog\u002Fblog\u002Fsuperposition-sequencer.md","Project Showcase: Superposition Sequencer",[7],"incomputable",{"type":9,"value":10,"toc":699},"minimark",[11,15,18,21,30,35,38,41,44,49,52,55,58,62,65,68,73,76,79,86,89,653,657,660,663,668,671,675,678,682,685,695],[12,13,14],"p",{},"Superposition Sequencer is a web-based quantum music tool that turns superposition and entanglement into something you can hear.",[12,16,17],{},"The interface looks like a normal sequencer, with drums, percussion, chords, and melodies. But the notes are not programmed directly, they are generated by running quantum circuits live on IonQ hardware, with a simulator as a fallback. You design a circuit in a visual editor, and its measured output drives the pattern: pitch, rhythm, velocity, timbre.",[12,19,20],{},"We're building Qollab with one question in mind: what does quantum computing look like outside the lab, in practical use across different industries? Superposition Sequencer answers that nicely for the music industry.",[22,23,27],"pull-quote",{"avatar":24,"name":25,"role":26,"username":7},"\u002F_content\u002Fimages\u002Fbuilders\u002Ffrancisco-estivallet.webp","Francisco Estivallet","Creator, Superposition Sequencer",[12,28,29],{},"I don't work with quantum regularly, but every few years I go back to it, study it a little, and get my mind blown. Then I forget about it, come back, and it happens again.",[31,32,34],"h2",{"id":33},"an-instrument-not-an-experiment","An instrument, not an experiment",[12,36,37],{},"Francisco's way in wasn't physics; it was history. The early days of computing and electronics, he points out, came with a wave of musical exploration that opened entirely new ways to make sound, with outsized cultural influence.",[12,39,40],{},"Francisco believes that quantum is in a similar moment, and that the way to meet it is to make it less intimidating. Of all his quantum-and-music ideas, a sequencer felt like the most approachable first step.",[12,42,43],{},"Here the composer builds the circuit, and the quantum hardware is the instrument. Superposition Sequencer also leans into something most engineers spend their time trying to eliminate.",[22,45,46],{"avatar":24,"name":25,"role":26,"username":7},[12,47,48],{},"In sound design, people are always looking for ways to make things sound a little imperfect. That little bit of noise is also a characteristic of quantum computers, so it could bring a new personality to the sound itself.",[12,50,51],{},"The sequencer is built for producers to generate full tracks, not just fragments. You can export a run as MIDI and drop it straight into Ableton or any other music software.",[12,53,54],{},"Circuits and the patterns they generate can be exported, saved, loaded, and reused, so you build up a personal library of quantum musical ideas, much like a hardware synth's patch memory.",[12,56,57],{},"A downloadable library of pre-executed sequences even lets musicians use the output without their own hardware access.",[31,59,61],{"id":60},"how-francisco-built-it","How Francisco built it",[12,63,64],{},"Francisco's first prototype looked nothing like a sequencer. It was a rotating sphere whose cursor struck different notes as it turned, leaning on the geometric way we usually picture quantum states. It didn't fit the metaphors he was after, so he went back to something more familiar: a step sequencer where each track line is a single shot of the circuit.",[12,66,67],{},"Under the hood, Qiskit builds the circuits and each run, on IonQ or the local simulator, produces probability distributions or entangled measurement outcomes that map onto musical parameters: pitch selection, rhythm, velocity, timbre. The circuits are fully parameterized, so you can modify them without a full recompile and explore how each change reshapes the sound. Entanglement has its own audible signature: the sounds of two entangled qubits are ring-modulated against each other. A correlation you would otherwise read off a chart becomes something you hear.",[22,69,70],{"avatar":24,"name":25,"role":26,"username":7},[12,71,72],{},"Each line is one shot of the circuit. It's that randomness and change between shots that creates the beat.",[12,74,75],{},"On the audio side, Tone.js handles sample-accurate scheduling, synthesis, and effects, all fed by the quantum-generated modulations. The app is fully serverless: a SvelteKit front end (with Threlte and Three.js driving the live Bloch spheres) talks to a stateless FastAPI service running Qiskit, which builds the circuit, extracts each qubit's Bloch vector layer by layer, and samples outcomes from the full statevector. Qiskit Aer and IonQ sit behind the same API.",[12,77,78],{},"To keep it responsive, frequently-used patterns are precomputed and cached while rare or highly-parameterized circuits trigger fresh hardware runs, balancing hardware cost against live interactivity.",[80,81],"blog-figure",{"caption":82,"no":83,"poster":84,"video":85},"Building a circuit in the visual editor and hearing it drive the sequencer. Press play, sound on.","Fig. 1","\u002F_content\u002Fimages\u002Fsuperposition-sequencer\u002Fscreenshot.webp","https:\u002F\u002Fapi.cms.qollab.xyz\u002Fassets\u002F2b1e9e5e-f28d-4ce2-8374-c59cdb281806",[12,87,88],{},"The same circuit renders to music outside the browser, too. This is the gist of the script you can copy onto Qollab's Playground to turn a circuit into a MIDI file: each qubit is a track, each shot is a beat, and a separate track writes how entangled each pair of qubits is as a MIDI control signal.",[90,91,95],"code-block",{"name":92,"run-href":93,"tag":94},"render_midi.py","\u002Fu\u002Fincomputable\u002Fsuperposition-sequencer","Python",[96,97,102],"pre",{"className":98,"code":99,"language":100,"meta":101,"style":101},"language-python shiki shiki-themes one-dark-pro","# 'backend' is pre-created as a global on Qollab\nfrom qiskit import QuantumCircuit\nfrom qiskit.providers.jobstatus import JobStatus\nimport time, random\n\nNUM_QUBITS = 4\nBPM = 104\nSHOTS = 104  # 104 shots ≈ one minute at 104 BPM\n\n# qubit index → instrument (each qubit is a track)\nSOUNDS = {0: \"clap\", 1: \"clap\", 2: \"bell\", 3: \"tom\"}\n\n# Build the circuit. Each layer (column of gates) is a beat.\ncircuit = QuantumCircuit(NUM_QUBITS, NUM_QUBITS)\ncircuit.h(0)\ncircuit.h(2)\ncircuit.ry(0.976411, 3)\ncircuit.cx(0, 1)\ncircuit.measure(range(NUM_QUBITS), range(NUM_QUBITS))\n\ndef main(shots=SHOTS):\n    job = backend.run(circuit, shots=shots)\n    while job.status() is not JobStatus.DONE:\n        time.sleep(10)\n    counts = job.get_counts()\n\n    # Each shot is one beat. Rebuild an ordered shot list from the counts,\n    # then shuffle so identical outcomes aren't clumped at the start.\n    shots = []\n    for bits, c in counts.items():\n        shots.extend([bits.replace(\" \", \"\")] * c)\n    random.shuffle(shots)\n    write_midi(shots)\n","python","",[103,104,105,114,131,144,152,159,173,184,198,203,209,263,268,274,299,329,342,366,392,421,426,448,482,512,528,544,549,555,561,572,593,627,639],"code",{"__ignoreMap":101},[106,107,110],"span",{"class":108,"line":109},"line",1,[106,111,113],{"class":112},"sV9Aq","# 'backend' is pre-created as a global on Qollab\n",[106,115,117,121,125,128],{"class":108,"line":116},2,[106,118,120],{"class":119},"seHd6","from",[106,122,124],{"class":123},"sn6KH"," qiskit ",[106,126,127],{"class":119},"import",[106,129,130],{"class":123}," QuantumCircuit\n",[106,132,134,136,139,141],{"class":108,"line":133},3,[106,135,120],{"class":119},[106,137,138],{"class":123}," qiskit.providers.jobstatus ",[106,140,127],{"class":119},[106,142,143],{"class":123}," JobStatus\n",[106,145,147,149],{"class":108,"line":146},4,[106,148,127],{"class":119},[106,150,151],{"class":123}," time, random\n",[106,153,155],{"class":108,"line":154},5,[106,156,158],{"emptyLinePlaceholder":157},true,"\n",[106,160,162,166,170],{"class":108,"line":161},6,[106,163,165],{"class":164},"sVC51","NUM_QUBITS",[106,167,169],{"class":168},"sjrmR"," =",[106,171,172],{"class":164}," 4\n",[106,174,176,179,181],{"class":108,"line":175},7,[106,177,178],{"class":164},"BPM",[106,180,169],{"class":168},[106,182,183],{"class":164}," 104\n",[106,185,187,190,192,195],{"class":108,"line":186},8,[106,188,189],{"class":164},"SHOTS",[106,191,169],{"class":168},[106,193,194],{"class":164}," 104",[106,196,197],{"class":112},"  # 104 shots ≈ one minute at 104 BPM\n",[106,199,201],{"class":108,"line":200},9,[106,202,158],{"emptyLinePlaceholder":157},[106,204,206],{"class":108,"line":205},10,[106,207,208],{"class":112},"# qubit index → instrument (each qubit is a track)\n",[106,210,212,215,217,220,223,226,230,233,236,238,240,242,245,247,250,252,255,257,260],{"class":108,"line":211},11,[106,213,214],{"class":164},"SOUNDS",[106,216,169],{"class":168},[106,218,219],{"class":123}," {",[106,221,222],{"class":164},"0",[106,224,225],{"class":123},": ",[106,227,229],{"class":228},"subq3","\"clap\"",[106,231,232],{"class":123},", ",[106,234,235],{"class":164},"1",[106,237,225],{"class":123},[106,239,229],{"class":228},[106,241,232],{"class":123},[106,243,244],{"class":164},"2",[106,246,225],{"class":123},[106,248,249],{"class":228},"\"bell\"",[106,251,232],{"class":123},[106,253,254],{"class":164},"3",[106,256,225],{"class":123},[106,258,259],{"class":228},"\"tom\"",[106,261,262],{"class":123},"}\n",[106,264,266],{"class":108,"line":265},12,[106,267,158],{"emptyLinePlaceholder":157},[106,269,271],{"class":108,"line":270},13,[106,272,273],{"class":112},"# Build the circuit. Each layer (column of gates) is a beat.\n",[106,275,277,280,283,287,290,292,294,296],{"class":108,"line":276},14,[106,278,279],{"class":123},"circuit ",[106,281,282],{"class":168},"=",[106,284,286],{"class":285},"sVbv2"," QuantumCircuit",[106,288,289],{"class":123},"(",[106,291,165],{"class":164},[106,293,232],{"class":123},[106,295,165],{"class":164},[106,297,298],{"class":123},")\n",[106,300,302,305,308,310,312,315],{"class":108,"line":301},15,[106,303,304],{"class":123},"circuit.",[106,306,307],{"class":285},"h",[106,309,289],{"class":123},[106,311,222],{"class":164},[106,313,314],{"class":123},")",[106,316,319,320],{"class":317,"tabindex":318},"qg-help",0,"?",[106,321,324,328],{"class":322,"role":323},"qg-help__tip","tooltip",[325,326,327],"strong",{},"Superposition."," About a 50% chance this track fires on any given beat.",[106,330,332,334,336,338,340],{"class":108,"line":331},16,[106,333,304],{"class":123},[106,335,307],{"class":285},[106,337,289],{"class":123},[106,339,244],{"class":164},[106,341,298],{"class":123},[106,343,345,347,350,352,355,357,359,361],{"class":108,"line":344},17,[106,346,304],{"class":123},[106,348,349],{"class":285},"ry",[106,351,289],{"class":123},[106,353,354],{"class":164},"0.976411",[106,356,232],{"class":123},[106,358,254],{"class":164},[106,360,314],{"class":123},[106,362,319,363],{"class":317,"tabindex":318},[106,364,365],{"class":322,"role":323},"A rotation tunes how often this track hits: the \"how often\" knob.",[106,367,369,371,374,376,378,380,382,384],{"class":108,"line":368},18,[106,370,304],{"class":123},[106,372,373],{"class":285},"cx",[106,375,289],{"class":123},[106,377,222],{"class":164},[106,379,232],{"class":123},[106,381,235],{"class":164},[106,383,314],{"class":123},[106,385,319,386],{"class":317,"tabindex":318},[106,387,388,391],{"class":322,"role":323},[325,389,390],{},"Entanglement."," Tracks 0 and 1 fire together, though each one alone still looks like a coin flip.",[106,393,395,397,400,402,405,407,409,412,414,416,418],{"class":108,"line":394},19,[106,396,304],{"class":123},[106,398,399],{"class":285},"measure",[106,401,289],{"class":123},[106,403,404],{"class":168},"range",[106,406,289],{"class":123},[106,408,165],{"class":164},[106,410,411],{"class":123},"), ",[106,413,404],{"class":168},[106,415,289],{"class":123},[106,417,165],{"class":164},[106,419,420],{"class":123},"))\n",[106,422,424],{"class":108,"line":423},20,[106,425,158],{"emptyLinePlaceholder":157},[106,427,429,432,435,437,441,443,445],{"class":108,"line":428},21,[106,430,431],{"class":119},"def",[106,433,434],{"class":285}," main",[106,436,289],{"class":123},[106,438,440],{"class":439},"sb9H8","shots",[106,442,282],{"class":123},[106,444,189],{"class":164},[106,446,447],{"class":123},"):\n",[106,449,451,454,456,459,462,465,468,470,473],{"class":108,"line":450},22,[106,452,453],{"class":123},"    job ",[106,455,282],{"class":168},[106,457,458],{"class":123}," backend.",[106,460,461],{"class":285},"run",[106,463,464],{"class":123},"(circuit, ",[106,466,440],{"class":467},"s_ZVi",[106,469,282],{"class":168},[106,471,472],{"class":123},"shots)",[106,474,319,475],{"class":317,"tabindex":318},[106,476,477,478,481],{"class":322,"role":323},"Runs on a trapped-ion IonQ machine through Qollab. ",[103,479,480],{},"backend"," is provided for you.",[106,483,485,488,491,494,497,500,503,506,509],{"class":108,"line":484},23,[106,486,487],{"class":119},"    while",[106,489,490],{"class":123}," job.",[106,492,493],{"class":285},"status",[106,495,496],{"class":123},"() ",[106,498,499],{"class":119},"is",[106,501,502],{"class":119}," not",[106,504,505],{"class":123}," JobStatus.",[106,507,508],{"class":164},"DONE",[106,510,511],{"class":123},":\n",[106,513,515,518,521,523,526],{"class":108,"line":514},24,[106,516,517],{"class":123},"        time.",[106,519,520],{"class":285},"sleep",[106,522,289],{"class":123},[106,524,525],{"class":164},"10",[106,527,298],{"class":123},[106,529,531,534,536,538,541],{"class":108,"line":530},25,[106,532,533],{"class":123},"    counts ",[106,535,282],{"class":168},[106,537,490],{"class":123},[106,539,540],{"class":285},"get_counts",[106,542,543],{"class":123},"()\n",[106,545,547],{"class":108,"line":546},26,[106,548,158],{"emptyLinePlaceholder":157},[106,550,552],{"class":108,"line":551},27,[106,553,554],{"class":112},"    # Each shot is one beat. Rebuild an ordered shot list from the counts,\n",[106,556,558],{"class":108,"line":557},28,[106,559,560],{"class":112},"    # then shuffle so identical outcomes aren't clumped at the start.\n",[106,562,564,567,569],{"class":108,"line":563},29,[106,565,566],{"class":123},"    shots ",[106,568,282],{"class":168},[106,570,571],{"class":123}," []\n",[106,573,575,578,581,584,587,590],{"class":108,"line":574},30,[106,576,577],{"class":119},"    for",[106,579,580],{"class":123}," bits, c ",[106,582,583],{"class":119},"in",[106,585,586],{"class":123}," counts.",[106,588,589],{"class":285},"items",[106,591,592],{"class":123},"():\n",[106,594,596,599,602,605,608,610,613,615,618,621,624],{"class":108,"line":595},31,[106,597,598],{"class":123},"        shots.",[106,600,601],{"class":285},"extend",[106,603,604],{"class":123},"([bits.",[106,606,607],{"class":285},"replace",[106,609,289],{"class":123},[106,611,612],{"class":228},"\" \"",[106,614,232],{"class":123},[106,616,617],{"class":228},"\"\"",[106,619,620],{"class":123},")] ",[106,622,623],{"class":168},"*",[106,625,626],{"class":123}," c)\n",[106,628,630,633,636],{"class":108,"line":629},32,[106,631,632],{"class":123},"    random.",[106,634,635],{"class":285},"shuffle",[106,637,638],{"class":123},"(shots)\n",[106,640,642,645,648],{"class":108,"line":641},33,[106,643,644],{"class":285},"    write_midi",[106,646,647],{"class":123},"(shots)",[106,649,319,650],{"class":317,"tabindex":318},[106,651,652],{"class":322,"role":323},"Writes one MIDI track per qubit, plus an entanglement track where each pair's mutual information becomes a MIDI control signal.",[31,654,656],{"id":655},"learning-by-ear","Learning by ear",[12,658,659],{},"Beyond making music, the project is a way into quantum thinking. Concepts like superposition, measurement, and entanglement become tangible when they are mapped to something you can hear: experiment with a circuit, watch the probability distribution shift, and listen to the pattern change with it.",[12,661,662],{},"Francisco's hope is specific. Just as synthesizers once pulled artists into electronics and then software in search of new sounds, building real intuition along the way, he wants this to do the same for quantum.",[22,664,665],{"avatar":24,"name":25,"role":26,"username":7},[12,666,667],{},"Even if it doesn't necessarily explain a lot to you, it makes it less scary. You play with it and think, okay, this is not scary anymore. And then you feel more comfortable to go deeper.",[12,669,670],{},"Francisco is building Superposition Sequencer as an open-source project, including the circuits, the front-end code, example projects, and documentation. Developers can extend it into new domains, artists can remix it, and educators can adapt it for workshops, lowering the barrier to quantum while showing a genuinely new way to interact with it.",[31,672,674],{"id":673},"where-its-headed","Where it's headed",[12,676,677],{},"Francisco has a long list of where this goes: richer preset circuits built with quantum researchers, richer compositions and sound design with musicians, and a physical version you could play like a real instrument, something he is already eyeing for festivals. On the software side, he wants external signal inputs, a plugin for music software, and quantum-generated scales, chords, and instruments.",[31,679,681],{"id":680},"make-it-yours","Make it yours",[12,683,684],{},"If you want to hear what a quantum circuit sounds like, this is a good place to start. Superposition Sequencer is open for forking on both Qollab and GitHub, and there is a live demo you can play with right now.",[680,686,689],{"fork-href":93,"live-href":687,"title":688},"https:\u002F\u002Fsuperposition-sequencer.incomputable.io","Play a quantum circuit.",[12,690,691,692],{},"Fork the sequencer, build a circuit, and hear it run on real hardware. ",[325,693,694],{},"Everything here is open and yours to build on.",[696,697,698],"style",{},"html pre.shiki code .sV9Aq, html code.shiki .sV9Aq{--shiki-default:#7F848E;--shiki-default-font-style:italic}html pre.shiki code .seHd6, html code.shiki .seHd6{--shiki-default:#C678DD}html pre.shiki code .sn6KH, html code.shiki .sn6KH{--shiki-default:#ABB2BF}html pre.shiki code .sVC51, html code.shiki .sVC51{--shiki-default:#D19A66}html pre.shiki code .sjrmR, html code.shiki .sjrmR{--shiki-default:#56B6C2}html pre.shiki code .subq3, html code.shiki .subq3{--shiki-default:#98C379}html pre.shiki code .sVbv2, html code.shiki .sVbv2{--shiki-default:#61AFEF}html pre.shiki code .sb9H8, html code.shiki .sb9H8{--shiki-default:#D19A66;--shiki-default-font-style:italic}html pre.shiki code .s_ZVi, html code.shiki .s_ZVi{--shiki-default:#E06C75;--shiki-default-font-style:italic}html .default .shiki span {color: var(--shiki-default);background: var(--shiki-default-bg);font-style: var(--shiki-default-font-style);font-weight: var(--shiki-default-font-weight);text-decoration: var(--shiki-default-text-decoration);}html .shiki span {color: var(--shiki-default);background: var(--shiki-default-bg);font-style: var(--shiki-default-font-style);font-weight: var(--shiki-default-font-weight);text-decoration: var(--shiki-default-text-decoration);}",{"title":101,"searchDepth":116,"depth":116,"links":700},[701,702,703,704,705],{"id":33,"depth":116,"text":34},{"id":60,"depth":116,"text":61},{"id":655,"depth":116,"text":656},{"id":673,"depth":116,"text":674},{"id":680,"depth":116,"text":681},[707,708,709],"Qollab","Explore","Superposition Sequencer",[711],{"username":7,"name":25,"role":712,"avatar":24,"bio":713,"links":714},"Creative technologist · Incomputable","Francisco is a mechatronics engineer and creative technologist with 15+ years across robotics, industrial automation, data products, and interactive installations. Through his Barcelona practice Incomputable, he builds tools and prototypes for artists, designers, and research labs, recently with six installations at Dubai's Sikka Art Festival and a prototype for the EU S+T+Arts residency. He is faculty at IAAC and came to quantum from the creative-coding and sonification side rather than physics.",[715,718,721,724],{"label":716,"href":717},"Qollab ↗","https:\u002F\u002Fqollab.xyz\u002Fu\u002Fincomputable",{"label":719,"href":720},"Incomputable ↗","https:\u002F\u002Fwww.incomputable.io\u002F",{"label":722,"href":723},"LinkedIn ↗","https:\u002F\u002Flinkedin.com\u002Fin\u002Ffranciscoestivallet",{"label":725,"href":726},"GitHub ↗","https:\u002F\u002Fgithub.com\u002Fchicoe",{"username":728,"name":729,"role":730,"avatar":731},"nico","Nicolaas Spijker","Community manager, Qollab","\u002F_content\u002Fimages\u002Fbuilders\u002Fnicolaas-spijker.webp",null,"Francisco Estivallet built a music sequencer where every note comes from a quantum circuit you design, turning a quantum computer into a playable instrument.","Francisco Estivallet built a quantum music sequencer where every note comes from a circuit you design. A Qollab Creative Challenge project.",false,"md","Quantum Creative Challenge · Spring 2026",{"href":93,"label":739},"Fork the sequencer",{"image":84,"alt":741,"liveUrl":687},"The Superposition Sequencer studio: gate toolbox and quantum circuit up top, driving the per-qubit sequencer tracks and mixer below","news",{},"\u002F_content\u002Fimages\u002Fsuperposition-sequencer\u002Fscreenshot.jpg","\u002Fblog\u002Fsuperposition-sequencer","2026-07-05","6 min read",[],[750,757,764],{"username":751,"project":752,"title":753,"category":754,"thumb":755,"to":756},"cephasteom","quantum-patterns","Quantum Patterns","Music","\u002F_content\u002Fimages\u002Fquantum-patterns\u002Fscreenshot.webp","\u002Fexplore\u002Fquantum-patterns",{"username":758,"project":759,"title":760,"category":761,"thumb":762,"to":763},"lukeshim","entangled-body","Entangled Body","Art","\u002F_content\u002Fimages\u002Fentangled-body\u002Fscreenshot.webp","\u002Fexplore\u002Fentangled-body",{"username":765,"project":766,"title":767,"category":768,"thumb":769,"to":770},"q-inho","qave","QAVE","Education","\u002F_content\u002Fimages\u002Fqave\u002Fscreenshot.webp","\u002Fexplore\u002Fqave",{"title":772,"description":773},"Quantum Creative Project Showcase: Superposition Sequencer","A quantum music sequencer where the notes come from circuits you build, run on real IonQ hardware. Built by Francisco Estivallet for Qollab's Creative Challenge.","blog\u002Fsuperposition-sequencer",[776,777,778],"music","quantum","creative-coding","IFwOJ9FGaKvjeZ87_SYHIhdfrixziSgqWcQT4qzgFDQ",[],[],1787180370684]