Note: From May 22, 1948 to October 13, 1958, multiple charts (usually jukebox, DJ, and sales charts) were used, which explains the overlap in the dates of the charts. Because of the existence of multiple charts, some dates had more than one number-one song during the week.
December 7: "The Clouds" — The Spacemen (3 weeks)* - ALTON 254
For continuation, 1960 to present, start search here.
Gap in the chart
From November 30, 1963 to January 23, 1965 there was no Billboard R&B singles charts. Some publications have used Cash Box magazine's stats in their place. No specific reason has ever been given as to why Billboard ceased releasing R&B charts, but the prevailing wisdom is that the chart methodology used was being questioned, since more and more Caucasian acts were reaching number-one on the R&B chart. According to researcher Joel Whitburn, "there was so much crossover of titles between the R&B and pop singles (Hot 100) charts that Billboard considered the charts to be too similar. This does not mean that R&B artists stopped turning out hits. After all, it was during this 14-month period that Motown established itself as an R&B institution."
^Whitburn, Joel (2004). Top R&B/Hip-Hop Singles: 1942-2004. Record Research. p. xiii.