Hi Mike,

Glad I could help! Regarding the double-time thing, it's more of an audio engineering issue than music theory. Theory-wise, there's nothing wrong with shredding at 258 BPM, but any audio file will sound best when played as close to its original tempo as possible.

Playing them at double-time won't sound quite as bad as half-time though, since it's easier to speed up audio than slow it down.

Thanks
Kent
PG Music