“KILL TUNES.” The Leaving Trains. SST. It’s one narrow line between convoluted and eclectic, and Leaving Trains walks it, bends it and ties it into knots. Can a band combine the sweet humming of cello and violin, the fervor of the New York Dolls (without falling into the trendy glam-rock trip) and twangy folk a la Green on Red and make this rock ‘n’ roll salad bar palatable? The Trains pull it off with the audacity of Iggy and the Stooges. On their second LP, Falling James Moreland continues to write tunes that might fall into the realm of social commentary, but his songs about racism (“Black”) and the so-called revivals in rock (“10 Generations”) escape haughtiness. And long before Trains can bore you with a dig-this-big-crux statement, they break into a bottle-smashing barrage or a recital of the alphabet.