Complex sentence: The baritone is distinguished from smaller sizes of saxophone by the extra loop near its mouthpiece; this helps to keep the instrument at a practical height (the rarer bass saxophone has a similar, but larger loop).
Split into simpler sentences: The baritone is distinguished from smaller sizes of saxophone by the extra loop near its mouthpiece. This helps to keep the instrument at a practical height (the rarer bass saxophone has a similar, but larger loop).