Asking a musician for an improv track can be a great idea. They may bring elements to the table that you would never have considered. It can also be a disaster. You might hate what they’ve done and wonder how they could possibly think that sounded good.
How do you make sure you get the former result and not the latter?
That’s the trouble with improv tracks. Unless you know the musician very well, it’s a gamble (I’ve even had improv stems from well-known and trusted musicians that made me scratch my head, so knowing them well didn’t help).
The truth is, we all have off days. We all have better or worse ideas. We all interpret a project a little differently, which can be a great thing or a terrible thing. If you’re the songwriter, you’re in charge (or whoever is paying for the services is generally in charge, haha) so your vision should be carried out fully.
Generally, people hire me to do a lead vocal and/or harmonies, and I’ll include an improv or adlib track at no charge. That way they can pick and choose what parts they want to include if any, or leave the whole thing in. But let’s say someone hired me to do an improv track only, on a jazz track or something. I will, of course, do whatever I think is best for the song and try to make it exactly what they want, but if you have a specific idea of what you want the adlibs to sound like, please let me know! It’s so much easier that way and then you get exactly what you want. Play it out on an instrument or sing a rough sample. That way I get it exactly right the first time around.
If you’ve hired someone and they send the improv track back and you hate it, how do you resolve it? My advice is to listen to what they’ve given and see if any of it is salvageable. Can you cut some parts and move them around? If not, try filling out my Revision Sheet and resubmit to the performer. You can also subscribe to my mailing list to get the sheet for free. If you haven’t played a part out for them, try doing so now. Hopefully, you’ve already negotiated to getting at least one free edit (if not, don’t forget to do this at the beginning of hiring someone!) and they can knock it out of the park for you on the second take.
So, to recap: