Boz Scaggs has had a long and varied career, playing blues, singing soul music, recording hits with smooth grooves, and taking his time with his temperamental muse. The Essential Boz Scaggs features 32 songs that tell the story of his solo career. It starts, after his stint in the Steve Miller Band, with his Atlantic Records self-titled debut album. Duane Allman fires up “Loan Me a Dime” with his trademark guitar work. Scaggs moved to Columbia Records, where he released a number of fine albums, culminating with the sleek, sophisticated grooves of Silk Degrees, provided by the band that would become Toto. Six tracks appear here, including the hits “Lowdown,” “Lido Shuffle,” and “Harbor Lights.” The runaway success of those songs helped push Scaggs further into the frontline with tracks like “JoJo,” “Isn’t It Time,” “Simone,” and “Breakdown Dead Ahead,” all from his 1980 album Middle Man. After that success, Scaggs’ output slowed considerably. However, such latter-day tunes as “It All Went Down the Drain,” “I Just Go,” and 2013’s “Gone Baby Gone” prove that his voice still has miles to go before it’s done.