Does the Harmonium course teach solo playing or accompaniment?

Both. The Harmonium course prepared by KalaSudha teaches solo playing and sangat, accompanying a singer. Foundation builds bellows, touch, ragas and a first bandish melody, and Intermediate adds following a singer, lehra for tabla and first solo playing.

Advanced has a module for khayal accompaniment and a module for solo harmonium. The concert has 20 minutes of accompaniment and 10 of solo.