“X-Static” is the Foo Fighters song featuring Greg Dulli on guitar.
Dulli, frontman of The Afghan Whigs, contributed a guitar part while Dave Grohl was recording the material that became Foo Fighters’ 1995 debut album. Grohl played nearly every instrument on the album, making Dulli’s appearance a notable exception. “X-Static” is therefore often identified as the record’s only track featuring another musician.
The song was recorded during sessions at Robert Lang Studios near Seattle in 1994, before Foo Fighters had become a touring band with a settled lineup. Dulli was visiting while Grohl worked on the recordings and ended up adding guitar to the track.
This fact is easy to mix up because Pat Smear later became a prominent Foo Fighters guitarist, but he was not the guest musician associated with this original recording detail. Dulli’s contribution belongs specifically to “X-Static,” a track on the self-titled debut, rather than to “Good Grief,” “Wattershed,” or “Exhausted.”