Complex sentence: He augmented the E Street Band with a five-piece horn section, The Miami Horns, led by Richie "La Bamba" Rosenberg, an addition to the band that would be both highly visible and audible.
Split into simpler sentences: He augmented the E Street Band with a five-piece horn section led by Richie "La Bamba" Rosenberg. It was an addition to the band that would be both highly visible and audible.