Complex sentence: Harrison omitted his name from the list of performing musicians, leading to an assumption that he had merely produced and arranged the music; the 2014 reissue of "Wonderwall Music" recognises his contributions on keyboards and guitar.
Split into simpler sentences: Harrison omitted his name from the list of performing musicians, leading to an assumption that he had merely produced and arranged the music. The 2014 reissue of "Wonderwall Music" recognises his contributions on keyboards and guitar.