a song cycle about bees 

a fund that tops up musicians' travel costs if they choose to travel overland to a concert abroad instead of flying
a musicians' "halls of residence" in central London to allow musicians to live outside London, work in London and stay the night after the concert.

It would be set up with generous sponsorship from God knows where and maintained in part by musicians' yearly / monthly / weekly subscriptions

Complete with practice rooms, wifi, good coffee, herb garden
set up a local composting service to support a local community growers' association, all food collected on push-bikes with trailers, and composted efficiently in wormeries
go to Rome with Esther 

perform (I'd probably opt for the cello part) in a Beethoven piano & cello sonatas cycle on historical instruments
(all seven - thanks for the inspiration, Mats Lidstrom)

Play more Haydn quartets

convince my parents they'd love a dog

perfect the veggie scotch egg

play keys in an amateur trad jazz band
(possibly with jazz theorbo and gut string bass - still keen, Alex McCartney and Carina Cosgrave?!)

private & public sponsorship for Really Classical Relay

grow a pineapple

bring back duelling in Hyde Park (this time with supersoakers) between ungrateful critics and proud musicians  
an anthem for First Nations

keep bees like this man does

"Also Sprach Nietzsche"
A secular Lutheran cantata for voice, viol, accordion and possibly electronics with hints of Bach, Wagner, Strauss, Persian music and some quotes from Nietzsche's own compositions; libretto from "Also Sprach Zarathustra"

go palm oil free
(good luck with that one)

Like an idea?