Led Zeppelin has recently released a remastered version of "Black Dog" from the upcoming expanded "The Song Remains The Same" box set.
"Black Dog" is one of Led Zeppelin's most complex song to play. Led Zeppelin would have to be perfectly in sync to be able to perform the song live. Since the first live performance at Belfast's Ulster Hall in '71, it has become a staple and a fan favourite of their live concerts.
The complex riffs and varying time signatures that give a chaotic vibe to "Black Dog". To ensure they were able to perform the song live, Bonham would eliminate the 5/4 variation so that Plant is able to perform his a cappella vocal interludes consistently.
Listen to the remastered version of "Black Dog" below.