Complex sentence: Woolly Wolstenholme--whose mellotron playing was a trademark of the band's sound in the 70s--left in 1979 after the album XII. Woolly pursued a short solo career fronting Maestoso, before retiring from the music business to pursue farming.
Split into simpler sentences: Woolly Wolstenholme--whose mellotron playing was a trademark of the band's sound in the 1970s--left in 1979 after the album "XII". He pursued a short solo career fronting Maestoso, before retiring from the music industry to pursue farming.