LJ Rich, writing on her blog:
Now, I’d like you to imagine you’re chatting with your conversation partner. But instead of speaking and hearing the words alone, each syllable they utter has a note, sometimes more than one. They speak in tunes and I can sing back their melody. Once I know them a little bit, I can play along to their words as they speak them, accompanying them on the piano as if they’re singing an operatic recitative. They drop a glass on the floor, it plays a particular melody as it hits the tiles. I’ll play that melody back – on a piano, on anything. I can accompany that melody with harmony, chords – or perhaps compose a variation on that melody – develop it into a stupendous symphony filled with strings, or play it back in the style of Chopin, Debussy or Bob Marley. That car horn beeps an F major chord, this kettle’s in A flat, some bedside lights get thrown out because they are out of tune with other appliances. I can play along to every song on the radio whether or not I’ve heard it before, the chord progressions as open to me as if I had the sheet music in front of me. I can play other songs with the same chords and fit them with the song being played. Those bath taps squeak in E, this person sneezes in E flat. That printer’s in D mostly. The microwave is in the same key as the washing machine.
This is from a few years back, but I just came across it and found it fascinating.