Gopi chants the mantra "Bansuri" http://mein.yoga-vidya.de/profiles/blogs/bansuri-bansuri which you can find at our Yoga http://www.yoga-vidya.de Vidya Kirtanheft as number 162. Here is the text of this mantra with some parts in German too:
Bansuri Bansuri Bansuri Shyamaki
He Rama ... He Krishna ...
He Jesus ... He Buddha ...
O my Lord, ... be with me
O my Lord, ... set me free
O mein Gott, ... steh mir bei,
O mein Gott, ... mach’ mich frei.
Come on and sing along the mantra "Bansuri". Find more mantras like this at our Yoga Vidya Mantra Podcast at http://www.yoga-vidya.de/de/service/blog/category/podcast/mantra/
Om Shanti Om, yours Omkara