Yes! Mantras do work. You just need to have the right approach to Mantras and you need to know ho to use them. If you use the mantra correctly, that means right pronunciation, right music, right attitude, right understanding of the sound you are using, then a mantra will do its job. If you just go to a mantra concert and hope miracles, this is not going to happen, since these concerts are pure entertainment, basically a business. So the sacredness of a Mantra does not manifest in such places. Best is to remember that mantra is from India - so look for the source from India who may be able to transmit you the right spirit and the way this tradition is really used. One example in the west is the teacher and artist Manish Vyas, he is very sincere in his transmission and presentation.