Justin Bieber's father is not really a pop fan but prefers two other musical genres. Which ones?

Explanation

Justin's father is called Jeremy Jack Bieber. He is a former professional boxer and has worked in construction. Jeremy is not really a big fan of pop music but prefers classic rock and heavy metal. When Justin was younger his father taught him to play several songs on his guitar, including Bob Dylan's ”Knockin' on Heaven's Door”. He also taught him to appreciate great artists such as Jimi Hendrix and Van Halen.