Tempo · aka Beats per minute
BPM
BPM stands for beats per minute — the tempo of a track. Classic trance sits in a narrow window: progressive trance at 128–134 BPM, uplifting and epic trance at 136–142 BPM, and vocal trance at 134–140 BPM. 138 BPM is regarded as the genre's spiritual centre, which is why Armada's classic-trance sub-label is literally named Who's Afraid Of 138?!.
Tempo in classic trance is not just a number — it defines the subgenre. Under 132 BPM a record feels progressive; over 138 BPM it starts to feel uplifting; over 145 BPM it stops being trance at all and becomes hard trance or hardstyle. DJs mixing classic-trance sets typically pitch tracks within a ±3% range of their original BPM to keep phrasing intact, which is why Sasha and Digweed sets from the late 1990s stay locked around 130 BPM for two-hour stretches without ever feeling monotonous.