Nama and Rupa are Sanskrit terms for Name (nama) and Form (rupa). This is a primordial area of focus in the Upanishads. In modern terminology, we talk about resonance and the study of WAVES. Here are some interesting visualizations of what happens to matter as it is vibrated by sound.
A brief RESONANCE demonstration on YouTube, showing the way matter vibrates in the presence of sound. Interesting illustration of what mantras do to your subtle body.
Chladni Plate: Someone takes what looks like a violin bow and uses it to vibrate the edge of a metal plate with sand or sugar on it. The particles vibrate themselves into orderly patterns.
Another demonstration of Cymatics:
There are better videos out there. Just go to YouTube and type "resonance" or "cymatics" into the search engine.
One reason this phenomena is so interesting is that the shapes created on the vibrating plate resemble Tantric art – the geometric and impressionistic art that yogis have developed over the centuries to depict what they feel inside.
For thousands of years, yogis have said that each mantra has a corresponding yantra, a visual shape created by the sound. So it is very interesting to see that just by putting some powder, sand, or grains of rice on a steel plate, and then sending sound vibrations, you can generate the types of patterns seen in yoga-tantra art.
There is more about the interaction of mantras or vibrations and matter here, on this site. And also at the Meditation 24-7 website, which is where I have been putting notes for the Wednesday night class.