I struggled with the answer to this question for many years until I finally took the time to study the runs and licks of virtuoso jazz pianists like Oscar Peterson, Tatum, and Teddy Wilson. My findings clearly indicated that they all prefer to play their favorite runs and licks in specific keys.
For this reason, I don't entirely agree with jazz educators who recommend that their students always practice a run or lick in every key and with every chord. Although this is certainly a great exercise, due to the degree of difficulty, it may not be practical when the tempo is very fast in certain keys.
When I suggest that we practice runs and licks only in specific keys, I am only talking about those that are technically very demanding. As jazz musicians, it is, of course, necessary that we can play most musical motives and phrases in all keys.
The problem is with the keyboard Layout
A run or lick is easier to play when the fingers and hands move naturally. Unfortunately, the keyboard is not symmetrical, which often makes executing the same run with the same fingering in a different key near impossible at high speeds. Even when we choose a more comfortable fingering to accommodate this problem, it may still not feel great.
I recommend doing the opposite
Instead of transposing and practicing a run in unsuited keys, consider finding only those keys that are a good fit. Also, there's a very good chance you will find other chords that work with the run just as it is. This approach will save you a ton of work, and your muscle memory will thank you for it.
Conclusion
When I find a great run or lick, I am always concerned about finding out what other keys and chords I can play it with without breaking my fingers. However, I do not force myself to adapt it to keys that are not a good fit. Instead, I focus my practice on memorizing the keys and chords that work well with a particular run or lick. I wish I had started doing this a long time ago. The listener doesn't really care in which key I play a dazzling run. They simply enjoy seeing me do it. No one ever came up to me and said, " I would have really liked to hear you play run No. 5 in B major".
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What do you think about this topic? Do you practice every run or lick in every key, no matter how difficult it is?