And if you scan the "reality check" lists I posted above, you might notice that of the best selling albums of 1958,

Teresa Brewer had a whopping 6,
Frank Sinatra had 5,
Ella Fitzgerald had 4 (one with Billie Holliday).
Bing Crosby also had 4, and
The Mills Brothers also had 4.
The Ames Brothers, Pat Boone, Kay Starr, Connie Francis, and Dalida (who or what was Dalida?) all had 2.

And once again, take a look at the list of the 5 top selling albums of 1958.

1.South Pacific – Soundtrack
2.The Music Man - Original Cast
3.Gigi - Soundtrack
4.Sing Along With Mitch - Mitch Miller
5.Tchaikovsky: Piano Concerto No. 1 - Van Cliburn

The Kingston Trio was right up there with all the rest of the single sellers, including Alvin and the Chipmunks.