Distinguished SOTW Member, Forum Contributor 2016
It depends. One lick one chord? Most of the time I can smoothly play it around the cycle in about 5 minutes or less. Unless it is has a lot of accidentals, then it might take me 7. If it's a 4 bar phrase I can get there in about 10 minutes. Technical exercises (and transposition) like this are pretty easy for me and I think it's one of my strong suits. My trouble is using it spontaneously in a musical (not contrived way).I used to have a lot of trouble with memorizing licks, until I found out I should not expect it to "stick" by playing it a lot but I should to try to actively learn stuff.
It's going a lot better now but I'm not sure if I'm doing enough.
For example: I'm currently practicing 2 of greg fishman's etudes (elston avenue and stony island avenue form jazz etudes part 3), Elston avenue is particularly hard(208 bpm) so I'm playing it a lot anyway.
Should I try to memorize all of it? I want to "train" my memory to memorize stuff more easily
How long does it take you to learn a lick in twelve keys?
I have been practicing this kind of thing for years and make it part of my daily warm up routine. Most of the time it's just licks, I have taken bebop heads around the cycle too. I put the lick in the context of the key or the chord and understand the numbers. I, IV, Vs...and 1, 2, 3s. Once I have this understanding, putting it in another key is actually easy.
How simple is "Mary had a Little Lamb?" I bet you could do that in all keys once you realized it's just Mi Re Do Re Mi Mi Mi; 3212333. So, my suggestion is to start short, start small, start simple, but start.