Complex sentence: Lighthouse is a Canadian rock band formed in 1968 in Toronto which included horns, string instruments, and vibraphone; their music reflected elements of rock music, jazz, classical music, and swing.
Split into simpler sentences: Lighthouse is a Canadian rock band formed in 1968 in Toronto. Their sound included horns, string instruments, and vibraphone; their music reflected elements of rock music, jazz, classical music, and swing.