Bas gitarist i kontrabasist Mario Mavrin vrlo se rano počeo baviti glazbom.

U nižoj i srednjoj muzičkoj školi V. Lisinskog (Zagreb) učio je svirati violinu, a zatim bubnjeve, kontrabas i bass gitaru. Ubrzo postaje članom orkestra Stjepana Mihaljinca.

Nakon povratka iz Afrike, gdje je svirao u orkestru Karla Metikoša, 1969. godine postaje stalnim vanjskim suradnikom Big Banda HRT-a pod vodstvom Miljenka Prohaske. Kao bas gitarist je svirao u legendarnoj rock grupi Time. Godine 1970. počinje suradnju s Boškom Petrovićem te tako surađivao i sa Zagrebačkim solistima, Rucner Quartetom, Peterom Soaveom, Zagrebačkom Filharmonijom i Michelom Legrandom, a nastupao je i na renomiranim svjetskim i europskim jazz festivalima surađujući s glasovitim jazzistima poput Erniea Wilkinsa, Arta Farmera, Clarka Terryja, Sala Nistica, Giannija Bassa, Csabe Desea, Tootsa Thielemansa, Philipa Catherinea, N.H.O. Pedersena, Alvina Queena, Martina Drewa, Duška Gojkovića, Lewa Soloffa, Alberta Mangelsdorffa, Johnnyja Griffina, Helen Merrill, Kristiana Schultzea, Carlosa Wernecka, Petera Appleyarda, Garyja Burtona, Michela Legranda, Royja Brinkera i drugih.

1995. g. svirao je u triju američkog klavirista Johna Lewisa. Bio je član ansambla Jazzbina profesora Igora Lešnika. Višestruki je dobitnik nagrade Status Hrvatske glazbene unije za najistaknutijeg instrumentalista, bas gitarista. Uz sviranje bavi se tonskom režijom te godinama surađuje kao vanjski suradnik-ton majstor Koncertne dvorane Vatroslava Lisinskog, Kazališta Komedija i drugih.

A bass guitar and upright bass player, Mario Mavrin started his music engagement in his early age. During his elementary and high music school education at the Vatroslav Lisinski Music school (Zagreb) he played the violin, then the drums, doublebass and bass guitar. Very soon he became a member of Stjepan Mihaljinec orchestra.

Upon his return from Africa, where he played in Karlo Metikoš's orchestra, in 1969 he became a permanent guest collaborator of the HRT Big Band under the leadership of Miljenko Prohaska. As a bass guitar player he has played for the legendary group Time. In 1970 he started cooperating with Boško Petrović and along the way he has collaborated with Zagreb soloists, Rucner Quartet, Peter Soave, Zagreb Philharmonic and Michele Legrand and he has performed at many well-known world and European jazz festivals in cooperation with famous jazz players like Ernie Wilkins, Art Farmer, Clark Terry, Sal Nistic, Gianni Bass, Csabe Desze, Toots Thielemans, Philipe Catherine, N.H.O. Pedersen, Alvine Queene, Martin Drew, Duško Gojković, Lew Soloff, Albert Mangelsdorff, Johnny Griffin, Helen Merrill, Kristian Schultze, Carlos Werneck, Peter Appleyard, Gary Burton, Michele Legrand, Roy Brinker and many others.

In 1995 he played in the trio of the American piano player John Lewis. He was a member of the ensemble Jazzbina of the professor Igor Lešnik. Mario is a multiple time winner of Status, Croatian Music Union prize for the most prominent instrument player, bass guitar player. Together with playing he has been engaged in sound engineering and for years cooperates as a guest sound engineer for the Concert Hall Vatroslav Lisinski, Komedija Theatre and others.