Singing bowls work alone or in groups. The number required varies based on your goal. A single bowl is often what will be used for a lead into and out of meditation, as a touchstone in a ceremony or as an announcement tool to draw attention to start a meeting.
With two bowls you invariably have a high and a low. Our brains will automatically arrange the tones, however they are played we will perceive the sonic distance between them. If the tones are close enough to each a binaural beat effect can be created where you will hear a tone that is not there, a blend of the two created by your brain.
With three bowls the arrangement of tones gets even more interesting. When I create sets of bowls I make an even tempered arrangement, with congruent sonic distance between each bowl. On a random basis three bowls will be bunched either on the high or low side.
Size matters with how many you need. Planning on placing them on someone’s body and ringing them – which is a wonderful use – smaller bowls give you space for more bowls.
Seven bowls are often used in Chakra sets, this is one of the more popular number to have.
The real answer to the question “How many singing bowls do you need?” is how many will you enjoy! Lots of people start with one and find themselves, years later with 17! I’ve put large sets together, one of the videos on this site is a set of 144 bowls I sold to one customer.
How many bowls does Ryan need, personally? I can’t say exactly but I know it is more than 144.