Ireland’s Chieftains and California’s Ry Cooder have absorbed musical styles from Cuba to Mali to Newfoundland, so an album mixing Mexican and Irish sounds is hardly startling. However, the vibrant San Patricio, which tells the dark story of ill-fated Irish immigrant soldiers who abandoned the Yankee cause to fight for Mexico in the Mexican-American War of the 1840s, surprises simply because it’s so much fun. Joined by a slew of guests, including Linda Ronstadt and Lila Downs, Cooder and head Chieftain Paddy Moloney pump out irresistible party grooves that are a striking contrast to the defeat and death encountered by their real-life subjects.