Misc: The main circle and trilithons at Stonehenge are built of which rock?

Questions

Massive Attack's "Safe From Harm" features vocals from this female artist.?

She does guest vocals in 808 State's "Oops".?

This NBA low-post scoring machine is also a professional jazz musician.?

His production credits include U2's _Zooropa_ & James' _Laid_.?

Minimalist composer who covers Bowie tunes in the album _Low Symphony_.?