Discovered Jazz and Swing in middle school and have been a fan ever since. Collecting 78s, which I started about 35 years ago, has helped me expand my musical horizon. One of my areas of interest is now also the "ethnic" or foreign-language music on shellac that Columbia, Victor, and many other labels produced for immigrants to the United States between the 1910s and 1950s.
Another example where the B side ("Magic Moments") became a hit.
RCA Victor's December 30, 1957 ad in Billboard shows that "Catch A Falling Star" was supposed to be the A side. RCA's January 1958 ad in Cashbox instead featured "Magic Moments". And Billboard, Jan. 20, 1958, page 63 declared "Magic Moments" "currently the stronger side, with the proviso that the flip, "Catch A Falling Star", "is also hot."
In the end, though, "Catch A Falling Star" rose to #1 on the Billboard Charts, whereas "Magic Moments" climbed only to #4.
In the UK, however, "Magic Moments" became the #1 hit: starting on February 28, 1958, it topped the charts for eight weeks.(Malcolm Macfarlane's Perry Como bio)