American male vocal quartet. One of the top vocal groups of the 1950s with a repertoire centered on standards such as Moonglow and The Christmas Song showing an unusually free, improvisational approach to their harmony singing. Most known are Day By Day and It's A Blue World. A couple of membership changes brought Bob Flanigan, a cousin, into the fold alongside Hal Kratzsch, and suddenly the Four Freshmen were assembled in all but name, and that fell into place a little later.