Complex sentence: While with Wills he helped compose "San Antonio Rose", although his most famous composition, "Steel Guitar Rag", and his playing, along with that of Bob Dunn, popularized the steel guitar in the United States.
Split into simpler sentences: While with Wills he helped compose "San Antonio Rose". He in more noted, however, for his most famous composition, "Steel Guitar Rag", and his playing, along with that of Bob Dunn, that popularized the steel guitar in the United States.