Petri Keskitalo (b. 1972) is again a perfect example of the versatility of a musician and how to breake the boundaries of different music styles. Besides his main work as the voice leader of Helsinki City Orchestra, he has performed also with Radio Symphony Orchestra, as a soloist for the Lahti City Orchestra and as a chamber musician in several groups. Keskitalo has succeeded in many international music competitions and he was chosen as the Brass Player of the Year at the Lieksa Brass Weeks in 1998.

Although tuba is a pretty rare instrument in jazz music, Keskitalo has played besides Gourmet also in other jazzbands. One important contact has been guitarist-composer Jarmo Saari: Keskitalo has played on the debut album of Zetaboo, the live album Live Ballet of XL and the album A Tribute to Finnish Cinema of Filmtet. Keskitalo was also part of the live version of Filmtet that did a Finnish Jazz Federation's tour in fall 2003. Keskitalo has also been a member of trumpetist Esko Heikkinen's Super Brass -project since the beginning of 1990s.

Keskitalo has also performed rootful rhythm music in bluesguitarist-singer Baby Boy Varhama's Misc. Co band, both live and on the album Swing That Music! (2003). If UMO has needed a back-up tubist, Keskitalo has been a self-evident choise. This happened for example in a concert at Helsinki Festival in 2003 where UMO performed classics from Miles Davis and Gil Evans. Besides playing the tuba, Keskitalo has also composed actively and taught tuba in Sibelius Academy.