The Swarmandal is played by khyal singers, but with the fingers and generally for vocal accompaniment. The Swarmandal is tuned to the 3 octaves on a specific raga. The singers plays arpeggios of notes with its right thumb.
Swarmandal was used on The Beatles song "Strawberry Fields" to produce the chimes featured throughout. For this it would have been plucked with a guitar pick or something similar to give a brighter tone and sounds as though delay has been added as well as ATT (Automatic Triple Tracking). Swarmandal (AKA surmandal) also appears on George Harrison's epic Indian production: "Within You Without You".
With box and key
Tuning bead on each string