Who was better?
Belushi’s singing or Aykroyd’s harmonica and dancing?
You HAD to ask the tough question! :-)
I prefer to compare apples to apples.
Belushi’s signing was powerful and soulful and I argue that his pipes are better than Akyroyd’s. That said, Aykroyd had the footwork and could move better than Belushi (not counting John’s acrobatics). Aykroyd does a damned fine job blowing the harp.