Paul McCartney’s whispery clarinet voice is a soft delight on his 2012 collection of jazz-era song favorites, which includes a gently swung “Home (When Shadows Fall)” and a downright limpid “Always,” swooning with sweet orchestral swells. He’s playful and sappy on “It’s Only a Paper Moon,” played with plangent gypsy touches, and lightly rocking on a chipper “Ac-Cent-Tchu-Ate the Positive.” Best of all is “My Valentine,” his mournfully adoring addition to the canon that more than justifies its inclusion among the greats.