Lips is awesome, I'll say this: when I first saw him on TMS, I got excited because I play trumpet too. Lips made sense because there was the lady trumpet player in TMS orchestra pit, but she also played trombone (and when Lips landed in the orchestra pit, she stayed on the bone), and as far as a rock group is concerned; a horn section comprised of a sax and trumpet is a beautiful set up.
One thing that bothered me that I didn't realize until Lips Palisade action figure was released, was that he (and most other Muppets who play instruments) holds his trumpet wrong! This is because puppeteers are usually right handed, so their left hand would have to perform any arm rods, that means (I guess) that Lips holds his trumpet backwards. Just a note though; whether you're left handed or right handed, the trumpet is always held with the left hand while the valves are operated with the right.
As a trumpet player, I've evaluated Lips (or rather searched for the stage musician(s) who provided the trumpet part) and find him to be a great horn player with what sounds like a strong influence from ragtime and Dixiland Jazz. Any Muppet song that features the trumpet automatically jumps to my top spot. I've only heard the song "Just An Old Fashioned Love Song" from the Paul Williams episode, so I'm not aware if that's Lips or not, but that has one of my favorite trumpet solos of all times. A band I was in covered that version and I got to write out the parts for myself (on trumpet, which I had a blast playing) and a trombone player (who I kinda' snubbed a lot from and gave me all the fun stuff!).