is for Harmonica.
Playing the harmonica: item number 573 on the list of Things That Are Much Harder Than They Look.
And yet, every single time I pick one up, I'm convinced that I'm going to sound like Little Walters*.
* I googled "famous harmonica player".
A Clay Baboons Alphablog: 26 Things That Annoy Me, Confuse Me, Creep Me Out, or Otherwise Make My Life More Difficult.