Complex sentence: Len then went on tour with the "O-Bar-O Cowboys" and in June 1933 met Grace Arline Wilkins at a Roswell, NM radio station when she traded Len a lemon pie for his singing "Swiss Yodel" over the air.
Split into simpler sentences: Len then went on tour with the "O-Bar-O Cowboys" and in June 1933 met Grace Arline Wilkins at a Roswell, New Mexico radio station. She traded Len a lemon pie for his singing "Swiss Yodel" over the air.