He, along with his studio, make up "Hyper Monolith", or just "Monolith"...these guys have done basically every DB video since Super Butoden 1, as well as arranging "Cha La Head Cha La", performing "Battle Point Unlimited"...basically every electronic original Dragon Ball song, really.
Anyway, here are some of the "big names" he has worked with over the years:
Steve Lukather; lead guitarist of the band Toto, currently performing the theme to Budokai 2:

Simon Phillips; lead drummer of the band Toto, in Mr. Yamamoto's recording studio:

Mike Porcaro; bass player for the band Toto, in Mr. Yamamoto's recording studio:

Leland Sklar; a touring Toto bass player, performing Burst Limit's
theme song:

Emilio Castillo (in red); a prominent horn player, and founder of The Tower Of Power. Kenji Yamamoto is next to him:

The Tower Of Power (Kenji Yamamoto is in the middle); a 10 member American soul and funk based horn section and band. For over 40 years with changes in personnel over the years, they have performed their own material, as well as provided support for some of the most original and impressive acts in the world.

Hideki Matsutake; was the lead sound designer and synthesist of the highly influential Yellow Magic Orchestra in the early 80's. Him and Kenji Yamamoto have been friends for over 20 years, and have done the soundtracks for Dragon Ball games from Super Butoden 1 all the way to Budokai 3.

Hironobu Kageyama; I DO NOT need to say anything about this man.


Yuka; I can't remember what she did in the series, but she provided the backing vocals for Budokai 2's opening theme. She's been a friend of Kenji Yamamoto since his project the "Hit Song Collections".

Here are some bonus pictures of a few people in L.A, where they recorded:




I also have a theory;
the song "Solid State Scouter" was performed by the "Dragon Magic Orchestra"...ring any bells? What about the "Yellow Magic Orchestra", the popular Japanese electronic band that Kenji Yamamoto's close friend and musical partner, Hideki Matsutake, was the lead sound designer and synthesist in? This can't be a coincidence. So what I believe is, the "Dragon Magic Orchestra" is actually the "Yellow Magic Orchestra" in some sort of alias. Maybe Kenji and Hideki Matsutake got everyone together again to perform "Solid State Scouter"?