1936: Patsy Montana records “I Want to Be a Cowboy’s Sweetheart,” the first million-seller by a woman country-and-western singer.

1937: Bing Crosby (with Lani McIntire and His Hawaiians) records “Sweet Leilani.” It becomes Crosby’s first blockbuster hit, with sales surpassing 22 million copies.

1937: After years of riding the rails, folk singer Woody Guthrie settles in Los Angeles, taking a job as a radio host for $1 a day. Though he is remembered for “This Land Is Your Land” and “Roll On Columbia,” his more political songs make him the father of protest music.

1938: John Hammond, who would later discover Bob Dylan, Aretha Franklin and Bruce Springsteen, introduces boogie-woogie, rocking blues and gospel, and Count Basie’s prototypical R&B at Carnegie Hall at his first “Spirituals to Swing” concert.

1938: Mississippi bluesman Robert Johnson dies. His songs — “Me and the Devil Blues,” “Hell Hound on My Tail” and “Sweet Home Chicago” — later inspire generations of rock musicians.

1938: Tommy Dorsey and His Orchestra record “Boogie Woogie,” composed by Clarence “Pinetop” Smith in a old piano style based on eight beats to the bar. The style becomes extremely popular in the late 1930s and early ’40s.

1939: Cab Calloway, the “King of Hi-de-ho,” records his first million-selling disc, “Jumpin’ Jive.”