For a record that’s just 34 minutes long, Spider Bags’ “Shake My Head” (Odessa Records) has enough whiplash transitions and mutations to stock a half-dozen much longer albums, pinballing between overdrive frenzy, pure-pop stateliness, psychedelic freakouts, surf-flavored roots rock and plenty more on 10 tracks of garage-rock goodness. And Spider Bags is one of the featured acts at this weekend’s 10th annual WKNC Double Barrel Benefit at Raleigh’s Pour House, closing out Saturday night’s festivities. J. Kutchma’s Five Fifths, Lilac Shadows, Wesley Wolfe and others are also scheduled. Cover is $12 per night at the door ($10 if you buy online). See thepourhousemusichall.com for details.