Brands – M
- Mach One
- Maestro
- Mahalo
- Majestic
- Manhasset
- Mapac
- Marbel
- Marca
- Marco Raposo
- Margun Music
- Mari
- Martin & Co Guitars
- Matthias Hohner
- Mberg
- Megan Claire
- Mel Bay Publications
- Melos
- Mi-Si
- Michael Kelly
- Mighty Bright
- Mildew Designs
- Millant-Deroux
- Milo Stamm
- Mitropa Music
- MMX
- Mojo Cables
- Mollard
- Monarch
- Monopole Strings
- Montford
- Mooer
- MTR Audio
- Music Area
- Music for Kids
- Music Games
- Music Gift Portugal
- Music Gifts Company
- Music Sales
- Musicards
- Musichorus
- Musicwear
- Musikboutique Gudrun Kübler
- Musikverlag Holzschuh
- Musikverlage Hans Gerig KG
- Müsing
- Musisca
- Mustard
- MXR
- My Pads
- My World
