List of bands (21):

Mastodon
Megadeth
Memphis May Fire
Metal Church
Metal Factory
Metalite
Metallica
Michael Schenker
Michael Schenker Group
Ministry
Miscreance
Misfire
Monstrosity
Moonspell
Morbid Saint
Morningstar
Mortemia
Motionless In White
Motörhead
Moyra