For the second time in a week, Dave Grohl played a surprise concert.

Earlier in the week, he played the 9:30 Club with the Foo Fighters.  On Wednesday night, he was by himself in Nashville.  The Foo Fighters front-man tore through several of his songs on an acoustic guitar in front of about 100 people at the Bluebird Cafe, according to the Tennessean.

Grohl did not give a reason for the surprise show.  But, a camera crew was there.  It should be noted that when Grohl played a surprise show in April, with Nirvana, the cameras were also rolling.

Is Dave Grohl working on another documentary?  Perhaps something to go with the next Foo Fighters album?