Complex sentence: They began with three songs that were written with the intention to record an entire album of material that would be thematically linked to their childhoods: "Strawberry Fields Forever", "When I'm Sixty-Four" and "Penny Lane".
Split into simpler sentences: They began with three songs that were written with the intention to record an entire album of material that would be thematically linked to their childhoods. The initial results produced "Strawberry Fields Forever", "When I'm Sixty-Four" and "Penny Lane".