In all the years I've played, I've never much used the major pentatonic scale for soloing. Sure, I know a few classic/hokey country licks, but other than that - nope. Minor pentatonic, major and its modes, harmonic minor and *her* modes, diminished, chromatic, sure... but not the seemeingly lowly major pentatonic.
Then last night I was practicing over a I-IV groove (thanks, looper) and some Jerry Garcia riffs (I know, I sound like a guitard or something) started coming out, and lo and behold - they were major pentatonic city! Who'd have thought it? I always heard Garcia as a pretty sophisticated melodic player - ahd he was using this boneheadedly simple scale?

And those ideas led into melodic motifs from the Allman Brothers "Jessica" - also major pentatonic city, with some suburbs thrown around!
It was a gas. All these melodic ideas were just flowing, and sounding pretty sweet on a fretless bass.
I have new respect for the Major Pentatonic, and will be doing a lot more playing around with her starting now.