Meditation is neither a journey in space nor a
journey in time, but an instantaneous awakening.
- J. Krishnamurti

Chants
For young children:  Sitting in your circle start a chant use everyone's name and go round, everyone say there name round and round you'll find a rhythm picks up. When the energy is working you may change the chant to fun words such as play, dance, tickle make it up as you go round.
Another time you can start a chant of ma ma ma... or dad dad dad... words or sounds that bring you joy and watch the sound change..

For older children you can do a study of different mantras there meanings and feel the different sensations as you work together.

Mantra means: A power phrase or mystic sound-syllables composed of vowels and consonants.  Used for controlling and focusing the mind.  An aid to spiritualization.

Here are a few to start with:

*Om (ohm) Sanskrit. The original Mantra.
The root of all sounds and letters
'OM' is the boat that enables one to cross over the rivers of fear, 'OM' is the sound of true love; all other Mantras emerge from and recede back into the Supreme Mantra.  Its form and power are certainly worth knowing and perfecting.

*Om Mani Padmi Hum (ohm mah-nee pah-dmee hum)
Tibetan. Develops the compassion of the enlightened beings.

*Om Muni Muni (ohm mooh-nee mooh-nee
Mahamuni mah-ha-mooh-nee) Tibetan.
Healing
Shakyiamuni Soha (sha-kia-mooh-nee so-huh)

*Om Vajra (ohm vah-jrah Purifies all past
Sattva Uh saht-vuh hum) & present negativity

*Om Ah Hum (ohm ah hum) Purifies body, word and mind

*Om Tare Tutare (ohm tah-reh too-tah-reh
Ture Soha too-reh so-huh)
Brings inspiration and Fortune to ones goals.

*Ram (rahm) Indian. Brings truth, righteousness and virtue Male aspect

*Sita (see-tah) Indian. Female aspect of Ram
When repeated with Ram as Sitaram, embodies the energy of perfect union

*Om Namo (ohm nuh-mo Indian.
Narayanaya nah-rai-uh-nai-uh)
Brings strength & helps regain harmony in times of trouble

* Soham (so-hum) Indian. Means "I am That" Unifies with the Absolute

If you feel more in tune with pure sounds than words, humming can be very satisfying. You simply close your mouth lightly and hum a low and deep sound, keeping the same note all the way through.
-I got these sounds from Osho his book ' The everyday meditator'.