"Reflections” was the first Supremes record released under the new billing,
Diana Ross & the Supremes, and is also among the final singles to feature
Florence Ballard, who recorded vocals for the song during one of her last
studio sessions before she was fired on July 1.

Barry Gordy with the Supremes during a recording session

None of the Playboys played their instruments on the recording and 
Gary Lewis‘s vocals were heavily supported by overdubs from The
Ron Hicklin Singers, a group of Los Angeles studio singers. The
music was performed by a group of studio and session musicians
called The Wrecking Crew.

The Wrecking Crew

Gary Lewis and The Playboys today

Ray Charles

The song “What’d I Say” was improvised one evening late in 1958
when Charles, his orchestra, and backup singers had played their
entire set list at a show and still had time left; the response from
many audiences was so enthusiastic that Charles announced to
his producer that he was going to record it.

For the rest of his career, Charles closed every concert with the
song. It was added to the National Recording Registry in 2002
and ranked at number 10 in Rolling Stone ‘​s "The 500 Greatest
Songs of All Time".

According to guitarist Scotty Moore, when “Blue Suede Shoes” 
was recorded, "We just went in there and started playing, just
winged it. Just followed however Elvis felt." According to reports
confirmed by Sam Phillips, RCA producer Steve Sholes agreed
not to release Presley’s version of the song as a single while
Carl Perkins release was hot.