Yesterday had many highlights, but one of the best parts had to be when I sightread through the piano part to Arvo Pärt's "Fratres" while Hayden played the absurdly difficult cello part. A video for the violin/piano version is below. I think my favorite version is the arrangement for violin and orchestra/percussion, but I couldn't find that on the internets.
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so so so so so so so so so good.