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Hum to acid line
Hum a line and the page plays it the way acid house plays a bassline: one note at a time through a resonant filter, sliding where your notes touch, a harder hit on the beat.
Mika slides where your notes join and leans on the beat. The squelch is the filter, not him.Four ticks count you in at 123 BPM, then the microphone listens for two bars, about four seconds, and closes. Nothing is recorded or sent anywhere.
What an acid voice does to a hum
Acid house is built on one small box, Roland's TB-303 Bass Line from the early 1980s, and Phuture's “Acid Tracks” (1987) is the record that made its sound a genre. The 303 plays one note at a time, from a sawtooth or a square wave, through a resonant low-pass filter that an envelope sweeps down after each note. A hum is one note at a time too, which is why it fits.
The page moves your line so its middle note sits between F2 and E3, an octave above a sub bass, where the filter's whistle still comes through on a phone. It starts on Quantized, every note on its nearest 16th, because an acid line lives on 16ths.
Saw, square, or the sample
The 303 has two waveforms and so has the page: Saw, bright and buzzing, and Square, hollower and more wooden. Both are built here from oscillators so a held note holds. Acid sample is the app's own sampled acid bass, short and punchy, the one the door lands on. Tap a chip and the same two bars play again.
Slide and accent
On a 303 a step can slide into the next: the pitch glides there in the same short time whatever the interval, and the filter isn't struck again, so two notes melt into one squelch. The page slides wherever two of your notes touch with no gap; hum legato and you get slides, hum short notes and you get none. Accent makes a step louder and brighter; here every note that starts on a beat is accented, which is how a line pushes against the kick. Turn Slide off to hear every note struck on its own.
What's in the pack
Five MIDI files, one per timing, on channel 2, in your key and tempo, and five WAVs of the lines on the sound you chose with the slides as on screen, exactly two bars long, plus a README. A MIDI file carries no slide: on a 303 clone or a DAW's mono synth, turn on legato or glide and let the notes you want slid overlap.
The WAVs are rendered twice round and the second pass kept, so they loop clean. Change the BPM before you download and the WAVs follow; the slides keep their short fixed time.
Into your DAW
The MIDI goes on any mono synth with a resonant filter: a 303 clone, or Ableton's Analog, Serum, Vital, FL Studio's 3x Osc with a filter after it. Then automate the cutoff slowly over eight or sixteen bars: the sweep is half of what an acid line is.
Sources: the 303's saw and square and “Acid Tracks” (1987) from Wikipedia, Roland TB-303 and DJ TechTools; the fixed slide time and what accent does from DJ TechTools and Synthtopia.
Or hear it in a track
Hear it in a track opens Brumm with the line on the grid on the app's acid bass, under a beat. No account, no upload. For a deeper line two octaves down, use Voice to bassline.
Your voice stays on your phone: the tool reads it in the browser and keeps nothing. How the site counts visits.
Audio: your microphone, on only after you tap. The sound is analysed in this tab and never sent. Nothing about the audio reaches the visit count.