List of bands (20):

Łukasz Łyczkowski & 5 Rano
Machine Head
Maddie Rock Squad
Magnum
Majestica
Majesties
Malevolence
Mammoth
Marianas Rest
Marije
Masquerage
Masterplan
Mastodon
Megadeth
Memphis May Fire
Metal Church
Metal Factory
Metalite
Metallica
Michael Schenker