The most known mantra is the sound of AUM or OM and this is said to be the sound of the universe itself and practicing this chanting offers maximum resonance and ability to generate overtones within the human body. It is associated with the third eye, which is the focus for our intuitive abilities. Taking this simple mantra as a staring point we can note that it is a seed mantra in that it only has one sound in it rather that being part of a phrase and also that it can be associated with a part of the body. While the external chanting of the mantra has profound effect on the psyche and groups, it is also the case that the unvoiced mantra has, in fact, a deeper resonance and power so that mental repetition can be used in meditation.
Leading up to the Ajna or Third Eye chakra on the forehead are seed sound for the elements often used in conjunction with the main lower chakras as they progress upwards.
The base chakra or Muladhara chakra is associated with earth with it’s bija mantra LAM (this is pronounced as in LUNG) the key sound being the sound of that initial L consonant such that the tongue behind the upper teeth.
The second sacral chakra, Swadhisthana, associated with water has the bija mantra VAM (pronounced as in VUNG) with the V sound vibrating the lips as if making a FF sound.
The solar plexus or Manipura chakra, with element fire has sound RAM with a roll on the R produced by curling the tip of the tongue to the roof of the mouth.
Anahatta or the Heart chakra, with element air has sound YAM pronounced YUNG with the tongue against the soft palate at the front of the mouth.
Visshuddha or throat chakra associated with space is sound HAM with the HUNG sound coming from the back of the throat.
The toning of chakras and corresponding chakra points can be mapped onto the instruments and tones used in sound yoga. Some systems use the western tempered scale as a reference for the ascending chakras from C, which is an effective way of demonstrating, increased pitch/vibration. It is, however, often useful to work with tonal variation across more that one octave as a C that truly resonates with the base chakra would be necessarily deep and earthy!