Jack Paar in 1950

Jack Harold Paar (May 1, 1918 – January 27, 2004)

Jack Paar hosted The Tonight Show on NBC from 1957
to 1962. He paved the way for Johnny Carson and others
before leaving television while still in his prime.

Arthur Godfrey Time was a Monday-Friday show that featured Godfrey’s
monologues, interviews with various stars, music from his own in-house
combo and regular vocalists. Godfrey’s monologues and discussions 
were usually unscripted, and went wherever he chose. The program
remained a late morning staple with the Old Read Head on the CBS 
Radio Network schedule until 1972.
 

1948

Casey Kasem on the air at WJBK in Detroit

Kemal Amin "Casey" Kasem 

Former radio personality Casey Kasem is best known for being the host
of the nationally syndicated Top 40 countdown show American Top 40
and for playing the character Shaggy in the Saturday morning cartoon
franchise Scooby-Doo on CBS/ABC (1969-1986). Before fame, Kasem
served in the U.S. Army in Korea.

Sandy Kozel

X Minus One was a half-hour science fiction radio drama series broadcast
from April 24, 1955 to January 9, 1958 in various timeslots on NBC.

(#3) May 8, 1955

The program opened with announcer Fred Collins delivering the countdown…

Fred Collins