The Dirt Band seems to like multiple-record sets almost as much as Chicago does. But unlike the latter group, it almost never uses more vinyl than its ideas can sustain. An elaborately packaged three-LP summary of the Dirt Band’s first 10 years, this current collection is no exception. The program includes “Buy for Me the Rain,” the catchy debut hit from 1966; such later gems as “Mr. Bojangles” and “Ripplin’ Waters”; and an album’s worth of sterling new material.