90 BPM is typical for Downtempo, Ambient. One beat lasts 666.7 ms and a 16-bar phrase runs 42.7 seconds.
Top Downtempo tracks| 1 beat (1/4 note) | 666.7 ms |
|---|---|
| 1/8 note (delay) | 333.3 ms |
| 1/16 note | 166.7 ms |
| 1 bar (4/4) | 2.67 s |
| 16-bar phrase | 42.7 s |
| Half time | 45 BPM |
| Double time | 180 BPM |