merlin

A synth is a board with extensive sound editing features.Examples: Triton,Trinity,Karma,Roland XV line.They usually have a sequencer except the XV.You can arrange songs by recording sequences and then chaining them together for the final product.This is the way I did it for years until arrangers came along.Once you record your style you can use the poweful realtime chord accompaniment to audition chord changes on the fly giving you endless musical possibilities.You can't do that with synths and so you lose that spontaneity in writing.In addition the sound quality IMHO is equal to pro synths for the high end arrangers.In some the sound editing os pretty deep.So,IMHO, arrangers offer you more possibilities and may take a little longer to master.I hope this helps.