Buddy Holly's "That'll Be the Day" was the #1 song on the Billboard "Best Sellers" list on September 23, 1957 -- it was #3 on the "Top 100" list. It had actually been recorded nine months earlier when Holly was under contract with Decca records. Decca didn't release it and eventually terminated Holly's contract. Holly then went to Clovis, New Mexico to record in Norman Petty's studio. They again recorded "That'll Be the Day." After being passed on by several other labels, Coral / Brunswick agreed to release it. Since Decca owned the rights to Holly's earlier record, the Brunswick label released it accredited to The Crickets. This still causes some confusion today, as subsequent releases were credited to The Crickets on Brunswick and to Holly on the Coral label. "That'll Be the Day" was Holly's only number one record as his career was ended by a plane crash in 1959.
The September 23rd, 1957 list contains several other rock classics: "Diana," "Honeycomb," "Teddy Bear," and "Bye Bye Love" were all #1's. "Whole Lotta Shakin'" was a #1 on the Country and R&B charts. Pat Boone's "Love Letters in the Sand" had also been a top song the previous June.
But it was the decidedly non rock and roll "Tammy" that was the top song of September. It was just ending a five week stint in the #1 position and would spend 23 weeks in the top forty. It was sited as the #12 song for the year by Billboard and recognized as the best song of 1957 by Cashbox.