During his "normal human being" period (1951-1972) he spent his time as a child and as a club singer.
In his "oh my god I can't believe I'm in Deep Purple" phase (1973-1976) he worked as an adequate replacement to Ian Gillian in Deep Purple.
He later transitioned to his "I think I'm going to name a band after my penis" period (1977-1984) in which he started Whitesnake and achieved much overseas success, however in the U.S. most people we're too busy telling each other to "relax".
It wasn't until his "freebase cocaine and hairspray" period (1985-1991) that the U.S. finally took notice of him and his band.
When Whitesnake broke up in '91, Coverdale retreated to his "I think I'm going to cut my hair and act real serious" period (1992-2001) in which he cut his hair and acted really serious.
Finally, he made it to his "I'm a total effing rock legend and you know it" phase (2002-present) in which he has lightened up considerably, regrown his hair, and reformed Whitesnake.
David Coverdale lives in Lake Tahoe and is happily married to his (third, I think)wife.
Person A: Who is the greatest rock singer of all time?
Person B: David Coverdale.
Person A: Do you think David Coverdale's hair had an influence on Whitesnake's late 80s success?
Person B: Of course.