Hannes Grossmann (born 8 September 1982) is a German drummer who plays for German progressive band Alkaloid and for U.S. technical extreme metal supergroup Blotted Science. He was also the drummer during Necrophagist's Epitaph era and played with Obscura.
In 2003 Hannes Grossmann began to play drums in the technical death metal band Necrophagist and later recorded drums for the album Epitaph in 2004 which features complex polyrhythmic drumming and blastbeats of up to 240 bpm. Hannes stated in an interview on onlinedrummer.com that the drum lines were the ones previously programmed by Necrophagist frontman Muhammed Suicmez, which he played in (almost) exactly the same way, which was exactly one of the reasons Hannes left Necrophagist later on. Hannes left Necrophagist in 2007 to join the band Obscura, along with his Necrophagist bandmate, Christian Muenzner, and Dutch bass player Jeroen Paul Thesseling, that has previously played in Pestilence. In 2008, Obscura were signed by Relapse Records and have gone on to release the album Cosmogenesis which was met with very positive reactions and cracked the US Newcomer Billboard. On September 28, 2010, Hannes joined the instrumental metal band Blotted Science, which features Ron Jarzombek (Spastic Ink) and Alex Webster (Cannibal Corpse). With them, he has recorded on The Animation of Entomology EP, which was released in 2011. He is also a member of Ron Jarzombek's latest musical venture Terrestrial Exiled with bandmate and countryman Christian Muenzner as well as Spastic Ink bassist Pete Perez. He was also involved in recording Christian Muenzner's solo album, Timewarp, which also features Steve DiGiorgio. To complete the list of his 2011 releases, he has recorded Obscura's third LP, Omnivium, that was, once again, met very positively by the fans and critics alike.
Hannes also teaches online drum lessons, which include personally customized lessons as well as stock drum video workshops that focus on Metal drumming.
In 2014, he released his first solo album, The Radial Covenant, which features a plethora of guest musicians including Christian Muenzner, Jeff Loomis, Ron Jarzombek, Morean and Per Nilsson.