I 

MacFurse

Anderton
There's an easy solution if you don't need to change tempo too drastically...

No. Not too drastic at all. About 1.5bpm is all. I knew this could be done, but didn't think the quality would remain. Now, I'm excited to get back home and back to work and see how it goes.
 

That's only about 2%. Shouldn't be a problem at all. A few additional points:

• Select the correct algorithm prior to bouncing. It should default to Radius Mix but to verify, type A to open AudioSnap and check the Offline algorithm.
• The sound quality won't be good until you do the bounce.
• Stretching handles speeding up much more elegantly than slowing down. When speeding up, material is omitted. When slowing down, material has to be created that doesn't exist.
• This is particularly true for groove clips. A well-acidized 100 BPM clip will stretch down maybe to 90 BPM but up to 150 BPM if edited properly.
• If you want no artifacts from stretching, you can use the "varispeed" techniques I've presented here however that will alter the timbre. At extreme lower pitches, this produces the "darth vader" effect and at extreme higher pitches, the "mickey mouse" effect.

When I do a "sketching session" with my artists we establish THREE things- and these are ETCHED IN STONE before the artist leaves this session!!: Tempo, Key, and Feel! I'm very up front with my artists about this! I enforce to them that once they leave, and I start production, these things will NOT change!
The way I typically get the 'feel' is I drop in a drum track that "feels like the song". I'm a musician for a bunch of years and this is one thing I believe I do well. I get them to play along. (Usually, I tap tempo as they begin playing so I know about where the tempo is before I drop in the drum loop). I'll stop after the first chorus or so and ask them "how does it feel." Frankly, most of the time I'm very close to the tempo. Once we get VERY close we cut a bit of the song. I play it back and ask them about the tempo. If they say "It's good" I'll ask "if there's any way you'd go with the tempo- up a couple BPM or down, which way?" By this time we're pretty much on it. We cut the song, I play it back and ask AGAIN "how does it feel to you?" If they say "I'm good" then I tell them again, "the tempo, key, and this feel isn't going to change, are you good with it?" They either have to say yes or no (and we'd start again) but almost always, it's yes. They split and my gig starts. They come back for a vocal after I'm done producing the track.
So far, after 12 years of producing- full-time, and about 1000 songs, I've yet to have someone to complain! I guess every producer has a process and this is mine. It works. ...thought I'd share it to save you some grief down the road. ...and by the way, I'm pretty much an old-school cat myself.