Here's a music story from bygone days. It's from my book, Beethoven’s Anvil: Music in Mind and Culture, pp. 93-94.
A number of years ago I was playing trumpet with a rhythm and blues band in a bar in downtown Albany, New York. It was two in the morning and we were exhausted at the end of a five-hour gig. My chops were shot.
We decided to play one more tune, “Stormy Monday.” Normally I didn’t solo on that tune; however, it is a slow blues, and I dearly love a slow blues. So despite my exhaustion, I decided to take a chorus—one cycle through the tune. I started playing simple figures in the lower-middle register and then elaborated on those figures and moved to the upper register. I hit my climax at the penultimate bar of the chorus, as anticipated, and was ready to stop playing. But, the rhythm section wasn’t playing concluding riffs; they clearly expected me to play another chorus. If I’d had any sense I'd have ignored them and stopped. My lips were crying out in pain; if I played much more my lip muscles would surely fail.
I didn’t like the idea of following a good chorus with a mediocre one. I couldn't remain in the trumpet’s difficult upper register, nor could I drop back to the middle register and then build back up—the two most obvious options for constructing another chorus. In a split-split second I decided “oh, what the hell” and did a Sonny Rollins, dropping to the middle register, growling and flutter tonguing to make the nastiest, bluesiest sound I could. Another power had entered my playing. Captain cat went on the prowl and the music went into overdrive. Solid.
As the band stood around after the gig, several people came up to me and chatted, touching me on the forearm on their way out. But it wasn’t me they wanted to touch. It was the power that emerged during that second chorus.
This “other power” did not possess me as fully as Leonard Bernstein seems to have been possessed by composers of music he conducted. I was at least residually aware of who, what and where I was. But I was focused on the music to an unusual degree, and my playing had an unaccustomed edge and force.