Pyrotechnics with the MSGEQ7 and Arduino

Rubens tubes are popular standing wave demonstrations that have been used by some as music visualizers, but they suffer from the fact that only a small number of particular frequencies produce the sine waves that makes Rubens tubes so striking--the fundamental frequency of the tube and multiples of said frequency. Consequently, they provide a much less compelling visual display than I would like.

I intend to construct a device resembling an audio spectrogram out of 7 equal-length Rubens tubes, Arduino, and the MSGEQ7 Graphic Equalizer Display Filter, which is capable of dividing a mono audio signal into 7 bands and translating their amplitude into a DC representation of each band.

After passively summing a stereo signal to a mono signal, I would like to use the varying DC output of the MSGEQ7 to control the volume for 7 separate tone generators, each tuned to a different frequency, beginning with the fundamental frequency for the lowest band, up through the seventh multiple of the fundamental frequency for the highest band. These particular frequencies are dependent on a number of factors: the dimensions of the tube, the size and number of holes in the tube, and how hot the tube is. While the first two factors are constant, the latter will change as the tube is running, so the frequency of each of the tone generators will need to be manually adjustable. I would also like to manually control the baseline volume for each of the separate tones in order to dial down the low frequencies and dial up the high frequencies. The final effect will be that when music is played through the device, each tube will display a different sine wave that will vary in amplitude according to the relative amplitude of each band in the audio signal.

I have already constructed the Rubens tubes for this project, and have acquired seven 10W speakers along with the amplifier modules to drive them. Any advice on how to implement the electronics would be much appreciated, such as what arduino or microcontroller(s) would be most suited to this project, coding tips etc.