As mentioned below, our last kirtan was enhanced by this beautiful and ancient instrument, the tambora. I'm always delighted when Ranchor brings his to the kirtan, as it produces an almost 'mystical' sound as a background to the chanting.
There is a very technical explanation of the instrument here, if you're interested enough to read it - I had never realised how much there was to what seemed a rather simple construction of a gourd, a piece of wood and some strings - each of which only plays one note. As the article describes: "Every single string produces it's own cascading range of harmonics and at the same time builds up a particular resonance..." It's this which gives the effect of almost being in another dimension, when the tambora plays.
It's also intriguing that there are 'male' and 'female' tamboras! And there can be no doubt that Ranchor's is a male.