Have had some intrest wanting to know how this was done. It was time consuming but easy.
Used 2 large pieces of black poster board as the background. A pen light and a cloth napkin to cover the pen to reduce its harsh light.
Shutter was set to 30sec. Would put the pen in front of the speaker, click it on and begin drawing the wave. Usually could get 3-4 waves per shot. Took about 160 takes to get this one. Was a lot of fun. I've recorded/played music for years, so that helped.
Many thanks for all the nice comments.
Statistics
Place: 12 out of 142 Avg (all users): 6.0105 Avg (commenters): 7.0000 Avg (participants): 6.1200 Avg (non-participants): 5.9714 Views since voting: 1924 Views during voting: 333 Votes: 190 Comments: 6 Favorites: 1 (view)