The Pair Extrordinaire were Carl Craig on vocals and Marcus Hemphill on upright bass. They had five albums on Liberty, three of which were basically their concert/club routines. They played a lot of LA Clubs in the 60's, and also worked in San Francisco. They opened for Bill Cosby a lot (where I saw them) and made numerous TV appearances, and even turned up in two movies. Hemphill went on to write for the Cosby Show and passed away in 1986.
Unfortunately, there is no fan website(though there are still fans around), and, as far as I can tell, none of their stuff is currently available. Everybody agrees that they were incredible!