Why every DAW opens at 120 BPM

The arithmetic reason

At 120 BPM a beat lasts exactly 500 milliseconds. That single fact does more work than any musical argument. An eighth note is 250 ms, a sixteenth is 125 ms, a bar of 4/4 is exactly two seconds, and a 32-bar section is exactly 64 seconds. Every subdivision a sequencer has to draw lands on a whole or half millisecond, which means a grid at 120 BPM has no rounding error to hide.

Compare that with 100 BPM, where the beat is 600 ms and a sixteenth is 150 ms, also clean, or with 140 BPM, where a beat is 428.571 ms and every subdivision below it repeats forever. Software copes with all of them, but 120 is the one where the numbers stay legible to a human reading a timeline.

120 BPM is the only tempo in this table where the beat, the eighth, the sixteenth and the bar are all exact to the millisecond.

The musical reason

120 BPM sits precisely at the bottom edge of the range usually quoted for Allegro, which is where a tempo stops feeling moderate and starts feeling lively. It is the point on the scale where music becomes energetic without becoming hurried, which makes it a reasonable neutral default for a program that has no idea what you are about to write.

Be careful with that table, though. Those ranges are conventions, not measurements. Italian tempo words were in general use for about a century before a metronome made a beats-per-minute number practical, and no composer who wrote Allegro ever defined it as a number. Published range tables disagree by ten to twenty BPM at the edges. The 500 millisecond beat is a fact; the Allegro boundary is an agreement.

The reason nobody mentions: it is a safe default

A program that opens at a tempo has to pick one, and every choice is wrong for somebody. 120 has two properties that make it the least wrong option: it is fast enough that a loop does not feel sluggish while you audition sounds, and it is slow enough that a first take recorded against it is playable. A default of 90 makes everything you drag in sound heavy; a default of 160 makes everything sound frantic.

It also doubles and halves cleanly into the tempos a lot of dance music actually lives at. Half of 120 is 60, one beat per second. Double it and you are at 240, the top of what a click is still useful for. That symmetry means a producer working at 120 can switch to half-time or double-time feel without touching the tempo at all.

What the default costs you

Here is the part that matters in practice. If you never change the number, every song you write starts at the same speed, and tempo stops being a compositional decision. That is a real effect: a song written at 120 because the software opened there is a song whose tempo nobody chose.

The fix takes ten seconds. Before you record anything, find the tempo the song actually wants by singing or playing it and tapping along on the tap tempo tool, then set that number rather than the default. If the answer comes back as 118 or 126, use 118 or 126. There is nothing magic about round numbers except that they are easier to remember.

The same argument applies to A4 = 440 Hz

Tempo is not the only place where a default has quietly become an assumption. Concert pitch works the same way. A4 = 440 Hz is the ISO 16 standard and the default in essentially every tuner and synthesiser, including the ones on this site, but it is a convention rather than a law of nature: historically informed performance commonly uses around 415 Hz, the 19th century French diapason normal was 435 Hz, and many central European orchestras tune to 442 or 443 Hz today.

The gap from 440 to 442 is about 7.85 cents, which is small but audible when a fixed-pitch instrument meets one that can adjust. The note frequency chart lets you rebase the entire table onto any of those references, and every individual note page lists the same note at all six. The lesson is identical to the tempo one: know which of your numbers are measured and which are agreed.

Data used in this article

Every number in the tempo table above is arithmetic from 60000 divided by BPM, computed on the page rather than typed in. The tuning figures elsewhere on this site come from the open TuneStand dataset, 33 alternate tunings plus the standards, free to reuse under CC BY 4.0:

That table is generated from /api/tunings.json, the same file anyone else can fetch. If you want to build something on it, take it: the only condition is a credit line. See the dataset page.

Try it

Frequencies on this page are computed at build time from twelve tone equal temperament with A4 = 440 Hz, using the twelfth root of two (about 1.059463) per semitone. Nothing is typed in by hand. See the full method and sources. Maintained by FusionStudios. Last reviewed: 5 August 2026.