Complex sentence: "The Frayed Ends of Sanity" debuted live on the Metallica By Request tour in 2014, although the band had previously played segments during solos, impromptu jams, or in a "Justice" medley.
Split into simpler sentences: The Frayed Ends of Sanity debuted live on the Metallica By Request tour in 2014. Before this performance, the band has played segments during solos, impromptu jams, or in a "Justice" medley.