Loop Blocks — a free block-based music maker: snap ready-made loops onto a grid and finish a track in minutes
Guide — make a track from loop blocks in five steps
Choose Dance, Techno, House, Hip-hop or Synthwave on the left and click any block to hear it. Click it again to stop. The tempo chip sets the song to the speed the pack was made for.
Drag a block onto one of the eight tracks and it snaps to a bar. Press + on a block to add it to the selected track instead. On a phone, tap a block, switch to Song and tap the track where it should go.
Drag a block to move it. Pull its right edge to repeat it for more bars. Hold Alt while dragging to copy it, and click the ruler to choose where playback starts.
Select a track and turn the knobs under the song: pitch, filter, delay, reverb, drive, pan and volume. Use M and S on the track to mute it or play it alone.
The song is autosaved in this browser. Use File ▸ Save song for a file you can reopen later, or Export WAV to render the whole track to audio you can use anywhere.
What is inside the studio
Every block is built from synthesised sounds, so nothing is a recording.
- Packs
- Dance 138 BPM · Techno 130 · House 124 · Hip-hop 92 · Synthwave 108
- Types
- drums, percussion, bass, chords, leads, arpeggios and effects such as risers and impacts
- Key
- all pitched blocks are in A minor, and the KEY control transposes the whole song
The knobs under the song belong to the selected track.
- Pitch
- up or down twelve semitones, drums included
- Filter
- one knob: low-pass to the left, high-pass to the right
- Space
- delay locked to the tempo, and reverb
- Grit
- drive for warmth and distortion
Blocks repeat to fill the bars you give them.
- Length
- 16 to 128 bars
- Tempo
- 60 to 200 BPM, plus swing for a looser feel
- Play
- from the start marker, with an optional loop
- Undo
- the last 80 changes
They work while the pointer is over the studio.
- Transport
- Space play or stop · Enter stop · F fullscreen
- Blocks
- ← → ↑ ↓ move · - = shorter or longer · Delete remove
- Tracks
- 1 to 8 select · M mute · S solo
- Project
- Ctrl+Z undo · Ctrl+S save · Ctrl+E export
A free block-based music maker in your browser, explained
Loop Blocks is a loop-based song maker in the style of the music programs of the late 1990s. Instead of drawing notes, you snap ready-made musical blocks onto a grid: a drum pattern here, a bass line there, a chord loop and a melody on top. Each block is a short phrase of one to four bars that repeats for as long as you stretch it. It runs entirely in the browser on the Web Audio API, the sounds are synthesised while you play, and nothing is uploaded, so there is nothing to install and no account to make.
How do I make a track with loop blocks?
Start with the drums. Click a few drum blocks in the list to hear them, then drag one onto the first track and pull its right edge until it fills sixteen bars. Add a bass block on the next track, a chord block above it, and finally a lead or an arpeggio. Because every block fits every other block, you can keep trying combinations until it sounds right. The Examples menu has a finished starter song for each pack if you would rather take one apart and change it.
Which styles and sounds are included?
There are five packs. Dance has pumping kicks, rolling bass and big saw anthems at 138 BPM. Techno brings warehouse grooves, acid lines and dub chords at 130. House is four-on-the-floor at 124 with piano stabs and organ. Hip-hop mixes dusty boom bap and slow trap at 92 with Rhodes keys. Synthwave adds gated snares, wide pads and brass stabs at 108. Each pack has drums, percussion, bass, chords, leads, arpeggios and effects such as risers, sweeps, impacts and vinyl crackle.
Why does everything sound good together?
All pitched blocks are written in A minor and follow the same four-chord loop, A minor, F, C and G. Melodies stay on notes that work over each of those chords, and the one-chord bass lines and arpeggios fit all of them. That is why a Techno lead can sit on top of a Synthwave bass line and still sound intentional. The Key control in the top bar moves the whole song up or down by up to six semitones, so you can also match the range of a voice or instrument you plan to add later.
What can the track effects do?
Every track has its own set of controls. They change the sound of everything on that track and are saved with the song.
| Control | What it does | Try this |
|---|---|---|
| Pitch | Transposes the track by up to an octave either way, drums included | Drums down 5 semitones for a heavier kit |
| Filter | Low-pass to the left, high-pass to the right, one knob | Turn a pad left by a third for a muffled intro, then open it up for the drop |
| Delay | Echo locked to the tempo (dotted eighth notes) | 20 to 40% on a lead or an arpeggio |
| Reverb | Puts the track in a room | A little on claps and chords, a lot on risers |
| Drive | Adds warmth and then distortion | 10 to 20% on drums to make them hit harder |
| Pan and volume | Balance and level of the track | Keep bass and kick in the centre |
The master output has a limiter, so you cannot push the whole mix into distortion by accident.
Can I change the tempo, key and swing?
Yes. Drag the BPM value, scroll over it or double-click to type a number between 60 and 200. Every block keeps working at every speed because they are built on a grid of sixteenth notes. Swing delays every second sixteenth note, which is the quickest way to turn the Hip-hop pack from straight into loose. The tempo chip above the blocks sets the speed and swing the pack was designed for.
How do I save and export my music?
The song is autosaved in this browser, so it is still there after you close the tab. For a backup use File ▸ Save song, which downloads a small .loopblocks.json file you can open again on any device. To get audio out, press Export WAV and choose 16-bit, 24-bit or 32-bit float, 44.1 or 48 kHz and how long the reverb tail should ring. The file is rendered faster than real time in the browser with the same engine that plays the song.
Is there a fullscreen mode?
Yes. Press the Fullscreen button in the top bar, or F while the pointer is over the studio. The studio takes over the whole screen and the eight tracks grow taller to use the extra height, which makes arranging a long song much easier. Press Esc or the same button to leave. On an iPhone, where browsers do not offer true fullscreen for web pages, the studio fills the whole browser window instead.
Does it work on a phone or tablet?
Yes. On a small screen the studio is split into three tabs, Sounds, Song and Mix. Tap a block to hear it and to arm it, switch to Song and tap a track to place it. Tap a placed block to select it, then use the buttons below the song to move it, change its length, copy it or delete it. A long press opens the same menu as a right-click on desktop.
More music tools
Want to program every note yourself? Try the Retro Beat Studio with its step sequencer and mixer. Build drum patterns in the drum loop studio, make chiptune loops in the 8-bit studio, or play melodies on the online virtual piano. Everything is listed on the music tools page.