What separates a songwriter from a studio musician is emotional investment. An artist paints with his blood, whereas a hired hand runs to the art supply store. For 35 years, Eric Clapton has poured himself into blues, rock, pop, gospel and reggae. Despite his stylistic variance, Clapton’s demons have remained the substance of his art.

His finest work is rooted in his greatest tragedies — “Layla” is a plea of love to George Harrison’s wife Patti and “Tears in Heaven” is a memorial to his dead son Connor. This past year, Clapton’s uncle Adrian, whom he credits for his taste in music, passed away. Clapton’s new album, Reptile, a scenic tour of all his past stylistic excursions, is dedicated to Adrian’s memory.

Clapton delves into the inspiration that Adrian provided him, from the upbeat St. Louis blues of “Got You on My Mind,” to the intense R n’ B of “Broken Down,” to the straight pop of “Believe in Life.” As Clapton drifts between loneliness, anger and frustration, the sonic shades mingle and transform, the emotional intensity ebbs and flows.

Blues purists will dismiss this release as a watered-down follow-up to Supernatural, the tremendously successful breakthrough album of fellow guitar god Carlos Santana. But Reptile is not just a talent showcase, as were Clapton’s past two releases, Blues and Riding with the King. In the tradition of Layla and Other Love Songs, Reptile is an emotional-theme album.

Slowhand’s guitar work is more subdued than ever, focusing on subtlety, not power. Backed by worthy musicians and a soulful vocal group, The Impressions, Clapton uses the circular acoustic guitar patterns of his 1992 Unplugged as a springboard to noodle with light jazz and Latin ostenatos. The title track opener fuses Spanish fingerpicking with jazz chords over a samba beat.

Clapton finally breaks away from the safety of blues standards with a thoughtful and eclectic array of covers, including the driven reggae-funk of Stevie Wonder’s “I Ain’t Gonna Stand for It” and the bold but soft Motown of James Taylor’s “Don’t Let Me Be Lonely Tonight.”

The originals are just as adventurous — “Superman Inside” is a proud Southern rocker with faint overtones of country and early British rock.

Reptile is certainly not a classic but nonetheless reaffirms Clapton’s immense capability and audacity as a songwriter. The label ‘guitar god’ overshadows the emotional element in his compositions, but this album demonstrates why Eric Clapton will be inducted into the National Academy of Popular Music/Songwriters Hall of Fame this June.