When I was 14 I would have wanted to "shred at 220bpm" but today I wouldn't get my wallet out for that. What I really would pay for is help getting into the pocket.
Anyone who can read a guitar tab can play the notes of "Superstition" by Stevie Wonder. But simply playing the notes against a metronome sounds mechanical -- the song only comes to life when you get the timings right (both the note attack and decay have to be timed for a "swing.") A good swing will practically force your audience to start dancing to your music -- it's magical! But it's very difficult to learn because regular metronome practice won't achieve it.
If you're measuring "rush and drag" against a straight metronome, could you also measure against a swung time, perhaps against timings extracted from in-the-pocket songs we know and love?
Anyone who can read a guitar tab can play the notes of "Superstition" by Stevie Wonder. But simply playing the notes against a metronome sounds mechanical -- the song only comes to life when you get the timings right (both the note attack and decay have to be timed for a "swing.") A good swing will practically force your audience to start dancing to your music -- it's magical! But it's very difficult to learn because regular metronome practice won't achieve it.
If you're measuring "rush and drag" against a straight metronome, could you also measure against a swung time, perhaps against timings extracted from in-the-pocket songs we know and love?