OM
SI VA YA NA MA
YA NA VA SI MA
MA VA YA NA SI
 SI YA NA MA VA
 VA SI MA YA NA
OM

 
Memorizing this mantra is a challenge. It will focus your mind to do it. When I learned it, it took me several days. I was at the same time creating a melody for it to go with the singing bowls. To do this I looked at is as connected to the chakras. However there are only 5 syllables and 7 chakras. SI is then the crown and inner eye, both are linked to the higher self. The feeling of the sound VA connects to the power of communication, the throat area. YA is in expression of positive outgoing energy, like YA!, yes, and it seems to be good for the heart. NA is like the word no, creating definition, personal space and energy, power, this is the third chakra area. The souond MA is definitely the root, the mother, the earth, the base. It depends on how you want to look at things where you put the second chakra, together with power or with the root. So, when I made the song for this mantra, in general I made a scale with SI the highest note and MA the lowest. The music took it's own way, and does not strictly follow this theory. Try moving your hand placing it over the appropriate chakra area as you do the mantra. There does seem to be a logic to the movement of the energies, I do think it is for a purpose of awakening and exercising the flow.
It may make it easier to learn if you notice the repeat patterns. The first two lines end with MA. After that the first syllable of the subsequent line is the last syllable of the previous one. YA-NA is in every line, bringing heart energy into the personality-ego-third chakra. Go through it and move your hand to the centers as you say the syllables. See the flow of it, it is like an exercise moving the energies around, and it seems to have a purpose.
Usually you hear the mantra OM Namah SiVAYA. However, as has been pointed out to me this is backwards, and gives the earth or root energy first, physical before spiritual. The greatest misconception of all time, to think the physical comes before and is the cause of the spiritual. So better to start with SI and spirit and bring it into the physical. We are in essence divine beings and we are here to bring heaven to earth..
It is said by some that the mantra of SI VA YA NA MA, as given here, was given by the masters to "call in the masters". I would rather say it is to call in and re-awaken your divine true self. Remember to always put an OM at the beginning and the end. There then will be two OM's in between each set, as you repeat the mantra.
I have made two videos with this mantra, here (click here) are the links to see them on YouTube. You will get much better visuals if you get me to make you a DVD, ask me about that.