Here is a very crude circuit that I made for a portable cassette player to make LED's "dance" with the music. I tapped off a low level audio signal in the preamp circuit. Maybe a WRITE command to eeprom during ADC readings would allow you to store it in a PIC with eeprom. I used an 8-pin 12F675.

ANSEL = 0 'all inputs digital
CMCON = 7 'comparators off
DEFINE OSCCAL_1K 1 ' Set OSCCAL for 1K device
@ DEVICE MCLR_OFF, INTRC_OSC, WDT_ON, BOD_ON, PWRT_ON, PROTECT_ON
TRISIO = %00000001
GPIO = 0 'all outputs low
X VAR BYTE


START:
ADCIN 0, X
IF X > 2 Then High GPIO.4 : Pause 100 'on leds
IF X < 2 Then Low GPIO.4 : Pause 5 'low leds
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