Sasha Johnson began his musical training at age 16, studying brass chamber music and tuba with Sam Pilafian at the Empire Brass Seminar of the Boston University Tanglewood Institute. He went on to study at the University of Toronto with both Mark Tetreault and Murray Crewe of the Toronto Symphony Orchestra, with Toby Hanks at the Manhattan School of Music, and with Alain Cazes at the Conservatoire de Musique de Montréal. His additional private teachers have included Arnold Jacobs, Gene Pokorny, Mel Culbertson, Dennis Miller, and Richard Erb.

In 1997, Sasha was the first Canadian tuba player to be accepted to the Von Karajan Academy of the Berlin Philharmonic. This program trains a small number of young professionals in the sound, style, traditions, and standard of the Berlin Philharmonic Orchestra. Having begun his professional career in Berlin, Sasha went on to perform with many other European orchestras including the Berlin Symphony, Berlin State Opera, Radio Orchestra Berlin, Orchestre Symphonique de Radio France, Orchestre de Paris, Ensemble Modern, and Orchestre National Bordeaux. He has performed in such music festivals and concert venues as the Lucerne Festival, Festival d'Aix en Provence, Concertgebouw, Wiener Konzerthaus, Theatre Champs-Elysées, Schleswig-Holstein Musik Festival, Salzburg Festival, and BBC Proms, under such eminent conductors as Claudio Abbado, James Levine, Pierre Boulez, Kent Nagano, Essa-Pekka Salonen, Charles Dutoit, Kurt Masur, and Seiji Ozawa.

Sasha returned to Canada in 2001 and has established himself as a prominent performer and pedagogue. He performs regularly with many Canadian orchestras including the Orchestre Symphonique de Montréal, the Toronto Symphony and the National Arts Centre Orchestra . He is the instructor of tuba at The Royal Conservatory's Glenn Gould School and an instructor of low brass and chamber music at McGill University.