I was thinking that all of the instruments that link has had have always been lightweight and easy to carry. There's been the Ocarina, Spirit Flute, Harp, and the conductor's baton (not instrument, but you get the idea). Which is why I got the idea for the next zelda instrument! My vote is for the next game to be "The Legend of Zelda: The Ten Ton Tuba." Anyone else have cool ideas for dumb zelda instruments?
I think they should use some obscure/not so well known instrument, like the ocarina was to the general public, before OoT.
Failing that, I would love to have a harp again. But used... properly. Even the Harp of Ages from Oracle of Ages was used better then the Goddess Harp. Playing the Tune of Echoes was much more fun then strumming like an idiot unless the plot needed it.
Link a la mode. No not Link in fashion, Link with ice cream.
As a hopeful of working on the next Zelda game, I humbly submit these ideas and titles for Zelda HD:
The Legend of Zelda: The Kazoo of Debbie
The Legend of Zelda: Tingle's Magic Triangle
The Legend of Zelda: Ganondorf's Accordion
The Legend of Zelda: The Tale of Link's Beatboxing
The Legend of Zelda: The Piccolo of Seconds
The Legend of Zelda: The Double Bass Link Can't Carry
and of course Navi's Metronome (*tick* "Hey Listen!"...*tick*"Hey Listen!"....)