Metronome
Set a tempo and practice. The first beat of each bar is accented, so you always know where "one" is — which is the whole point when you are working on pocket.
Tap the buttons, or use spacebar and arrow keys on desktop.
How to actually use it
Most rappers use a metronome wrong: they turn it on, rap along, and stop when it feels fine. That trains nothing.
Try this instead. Set it 10 BPM slower than the beat you're writing to and deliver your verse. Slow tempo exposes rushed syllables — the ones you've been hiding behind the beat's energy. Fix them there, then speed back up.
Breath control
Run the same eight bars at increasing tempos until you can't finish a line without gasping. That ceiling is your real limit, and it moves up with practice faster than almost anything else in rap.
Related: find the tempo of any song · what BPM should a rap beat be · how long is 16 bars.
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