Look at how many great jazz players' last name begin with M.
In my collection, the biggest single artists areas are for Davis, Ellington, Parker, Rollins, & Coltrane, but the biggest single letter section by far is M, #13 of 26, smack dab in the middle.
M is for Monk/Mingus, that's good enough for me.
But there's SO much more!
Go ahead - go to any record store w/even a halfass jazz selection and see where the highest concentration of worthy artists is - it's under M. See if that holds true in your own collection as well.
M