“Regarding musical instruments, herein it is prescribed that for Nama Hatta programs it is not necessary to have big, complicated paraphernalia; mrdanga and kartalas are sufficient. Srila Prabhupada liked this type of simple kirtana with mrdanga and kartalas. At the same time, in bhajanas he would sometimes use the harmonium.
In kirtana, the beautiful melody, the music, and the beat all have a purpose. They should help to melt the heart, to evoke the dormat love for Krishna. Bhaktivinoda Thakura gives the analogy of the borax melting gold. He uses what at that time was a commonplace illustration, which indicates how rich society was then. Nowadays everything is plastic or aluminum – even women’s jewelry is often made of plastic – but in that day gold was very common.
I do not know exactly what happens when borax is applied to gold, but apparently it acts as a catalyst, causing the gold to melt much faster when heated. Similarly, kirtana should help the heart to melt naturally.”
Courtesy: ISKCON Congregational Development Ministry