I always play music in the background when I'm drawing.
In silence I tend to freeze. One drawing usually takes 2-3 hours.
These examples are also some of my favourites.
Claude Debussy: Nocturnes (1899)
Dmitri Shostakovich: Symphony No. 8 (1943)
Bernard Herrmann: Psycho (1960)
1960s Greek Avant-garde
Ennio Morricone: Drammi Gotici (1977)
Siege: Drop Dead (1984)
Diamanda Galas: The Divine Punishment (1986)
Thorns: Trøndertun (1992)
Thorns: Thorns (2001)
Virus: Carheart (2003)