Misc: When someone is a hanger on or serves no purpose, he is called this?

Questions

This ex Van Halen member did the song "The Girl Gets Around".?

This female musician wants you to "sing her a happy song"?

This former ac/dc member died on february 19, 1980?

This group has recorded covers of The Beatles classics "come together", "i am the walrus", "helter skelter", "help" & "day tripper"?

This group name suggests an unpleasant February 14th.?