These are the songs of the "Vaishnavas", those who study the Vedic literature (ancient indian books of spiritual wisdom) and practice it to different degrees. the words are spelled here phonetically, and are of the language Sanscrit. They are "Mantras", or prayers that are also sung. there are several standard melodies for each mantra that have passed through the ages through disciplic succession, and if you'd like to hear all kinds of live versions of them you can find them easily enough, I have included the names of the mantras above them.
nama om vishnu-padaya
svamin iti namine
namas te sarasvate deve
Pancha-Tattva Maha Mantra
Hare Krishna Hare Krishna
Krishna Krishna Hare Hare
Hare Rama Hare Rama
Rama Rama Hare Hare
Some people ask me (some don't, and form their own, uneducated opinion) what the practices of the Hare Krishnas are, or what they teach. Javier Fransisco Sanchez put it best when he answered such a question thusly: " Multiple dimensions, Quantum Physics, Sound Vibration, Reincarnation, Aliens, Spiritual ascension, and Cooking." of course, they only teach those who come to them. You won't find the Hare Krishnas going door to door. You certainly won't find them asking for money. However, You will find them distributing books and performing Kirtan (sung mantras) at the Alamo. You Will find them serving free spiritual food, Prasadam, every Sunday and offering programs and services to teach all that above crazy stuff and more. you will find them living in the temple, waking up at 430am for their first service. and if you need it, you will find them feeding breakfast, lunch and dinner, and will gladly give cooking lessons. The Hare Krishnas did not come here to take; they have come to give. They are not really interested in more money than it takes to keep their rent paid, they know it does not go with you when you leave this world, and they do not plan to stay here forever.
you will find them singing, dancing, chanting, praying, cleaning (every day the floor is mopped and carpets vacuumed. every day.), picking flowers, taking Japa walks (japa is chanting The Maha Mantra with beads, 108 beads make one round, the more rounds the better), burning incense, playing the Harmonium, Mrdunga, Karatalas, and other instruments, etc etc etc etc.
if you want to find out what you're missing, you know what to do.