Guitarist-vocalist Dan Rubinoff likes to joke that it only took him 50 years to write a good song. But once he did, he knocked out a bunch — 12 of which have landed on Pie Chart of Love, the stellar debut album Rubinoff and his partner, bassist-vocalist Joice Moore, will release on May 10 as the duo RubyJoyful. The Colorado-based outfit will begin a spring tour that night with a performance at Steve’s Guitars in Carbondale, Colo.