It takes audacity to title an album Punk Rock, but if anyone has the credentials to get away with it, it's the Mekons. Formed in Leeds in 1976, the band has undergone nearly as many personnel shifts as Guided By Voices, though Jon Langford and Tom Greenhalgh remain at the core. The group survived a continental transplant to become a beloved fixture in its adopted Chicago hometown, and it's tried on more styles than most acts have in their record collection. Punk was the first of these, but after making a loud, sardonic noise in punk's first wave, Mekons has tried it all. If punk above all means a rules-be-damned, try-anything approach, Mekons would have earned points simply for recording country music when it was the anathema of hip. The indirect product of a series of 25th-anniversary shows, Punk Rock takes the band back to square one for a set of songs written between 1977 and 1981. Some are new versions of tracks found on the first few Mekons albums, while others have never been recorded before, but they all benefit from the group's longstanding eclecticism. No mere retro exercise, Punk Rock finds room for a lot of diversity under the punk banner. Langford shouts with the spirit of '77 on "I'm So Happy" and other songs, but plenty of reggae and folk influences have also been thrown into the mix, suggesting that if The Clash hadn't thrown open the doors of punk with London Calling, Mekons would have pounded it open one inch at a time. Some of the songs have aged better than others, making this a better album for longtime fans than for newcomers. But even in its rougher moments, it's a joy to hear a band looking backward and discovering that it's as in love with making music now as the day it was formed.