A lot can be said for some instruments and the hands that play them. Sting's bass shows years of wear and tear (Bonnaroo, Manchester, Tenn., June 14-17); Tom Morello's acoustic bears a simple, meaningful message (Bonnaroo, Manchester, Tenn., June 14-17); John Butler's nails help him hit the right notes (Bonnaroo, Manchester, Tenn., June 14-17); Derek Trucks finds no need for a pick (Allman Brothers Band, Verizon Wireless Amphitheatre, Aug. 10); and no guitar shows more personality than Willie Nelson's (Cabarrus Arena, Aug. 22).