If you’re looking for a record label to do your deep crate-digging for you, look no further than Omnivore Records. The musical archaeologists there have unearthed three all-but-unknown records from artists on the fringe. But these fresh and vital discoveries from Sid Selvidge, Sandra Rhodes and Todd Cochran a.k.a. Bayeté will likely leave you wondering, “How have I missed this music until now?” Likely on the strength of his work on Bobby Hutcherson’s 1971 Blue Note LP Head On, composer-pianist Todd Cochran was signed to venerable jazz label Prestige. The very next…