Complex sentence: Many of Goodman's hits from the swing era were played by Henderson and his own band in the late 1920s and early 1930s, and usually were head arrangements that Fletcher transcribed from his own records, then sold to Goodman.
Split into simpler sentences: Many of Goodman's hits from the swing era were played by Henderson and his own band in the late 1920s and early 1930s. In fact, they usually were head arrangements that Fletcher transcribed from his own records and then sold to Goodman.