Complex sentence: While touring Scandinavia he first joined forces with guitarist and singer Peter Thorup, together forming the band New Church, who were one of the support bands at the Rolling Stones Free Concert in Hyde Park, London, on 5 July 1969.
Split into simpler sentences: While touring Scandinavia he formed the band New Church with guitarist and singer Peter Thorup. They subsequently were one of the support bands at the Rolling Stones Free Concert in Hyde Park, London, on 5 July 1969.