Hmmm, beach, sea and volcano/mountain... So perhaps Albatross, Shark and Bear Zords? Hmmm... What other things could work... My other suggestion for it is to just steal the Liveman suits and mecha, but whilst dolphin fits the sea theme, lion and falcon fit it a little less so. Although lion would fit "sand", and I guess falcon could be conflated with the phoenix somehow and end up representing volcano, but...

Still not entirely sure what music rangers' Zords would be, though. ^^; Hmmm.