Quartet No.5 / Quartet No. 6

Cover is orange and white. Catalog no. is given as ML 4280 on the front and back covers, as ML 54280 on the labels. Labels dark blue with silver text. "Columbia" (above) and "Long LP Playing" (below) outside the inner ring. As shown. Differs from [r3718275], which has magenta rather than orange blocks of color on the cover and in that it says "Long LP Playing" at label bottom with no mention of "Microgroove".