[3] He presents a weekly program on NTV Uganda,called "Jazz with Isaiah".

[9] Katumwa is a self-taught saxophonist[10] who made a breakthrough in music through his album Sinza in 2006 which featured on the BBC.

[11] He has performed alongside popular Ugandan musicians/outfits like the Afrigo Band, Eagle's Production, Ndere troupe, Crossroads Band, Fred Sebatta, Paul Kafeero, Juliana Kanyomozi, Mariam Ndagire and Steve Jean.

Katumwa has also worked in conjunction with actors like Alex Mukulu, Kato Lubwama, and Abbey Mukiibi.

When he went to secondary he started studying music while playing in the Primary school Brass Band.

“Sinza” was featured on "BBC focuss on Africa" and opened doors for him in different countries.