John Lee Hooker was famous for not being able to have a bass player with him, because he would play the blues with 11 or 13 bars thrown in a song.
I wish I could find the source, but the interview as I remember it went like this,
JLH: "Of course I know how to count. I can count to 12. But I don't count my music, I feel my music. And if it needs 11 bars or 9 bars, that is what I give it. And if it needs more that 12, I do that, too. Not everybody can play with me because of that."
My memory is rapidly being overtaken by my forgettory, so I cannot recall the source for this. I will do a little digging.
It would be well to get a correction. To quote rather than garble recollection. I shall hunt in my liner note collection.
It is, of course, not about an alto saxophone, but there was a direct question about 11 bars in a blues form.