Gregorian chanting is generally associated with religion and involves many people chanting in low tones simultaneously. Most chants that are found and performed today are from 900 to 1300 A.D. The sounds are simple and it is occasionally linked to the primordial sounds used in Tibetan meditation. Most recently, Dr. Alan Watkins, senior lecturer in neuroscience at Imperial College London, states that there is a link to Gregorian chanting and lowering blood pressure. There are similar studies linking meditation to lowering blood pressure and it is not clear if these factors are related.
Many baroque pieces cause the physical body, heart rate and muscles to relax and slow. When this happens, the mind is better able to focus on the meditation. This music affects the "amplitude and frequency of brain waves, which can be measured by an electroencephalogram. Music also affects breathing rate and electrical resistance of the skin," says Laurence O'Donnell III, a musicist (he plays the bassoon) from Perth, Scotland.
Not traditionally considered music, sounds of nature are often regarded as excellent music for meditation. Many people find that meditating in nature helps them attune themselves and find an inner balance. For this reason, CDs that feature nature sounds, sometimes in combination with classical music, are very popular choices for meditation aids.
Primordial sounds, similar to Gregorian chants, are more tonal than they are musical. Meditating with the use of primordial sounds is supposed to balance and center the person meditating and also clear them of negativity. There are several primordial sounds, the most popular being; a, om, oo and m. By utilizing music that incorporates the primordial sounds, the person is said to be led into the meditation by the sounds.
Not strictly music but available on CDs in many locations, consumers can obtain guided meditation sounds. These will include a calm voice leading the person into meditation. This type of meditation is often focused on imagery to help calm and relax the body.