Nerves & Intonation

"But I played it in tune at home - why was it so out of tune in the recital?" Nerves cause tension, tension causes left hands to squeeze, squeezing a hand makes your hand and fingers tight. Tight hand and fingers are slower to adjust to a pitch, and make it harder to shift, and the distance between the fingers change from your normal more relaxed left hand position - hence wacky intonation. Constantly check for left hand tension. Release. Release. Release.