The Amazing Slow Downer

If you are a serious musician, you probably have run across the problem of how one learns difficult music that is played quickly. Trying to play along with a recording can be an exercise in extreme frustration. New guitarists in particular struggle with this. The real obstacle is that you cannot just play the recording back at a slower speed, since that will change the pitch. The issue can be a show-stopping bummer in trying to master a new song.

A few months back I ran across a reference to a software application that changes all that, the Amazing Slow Downer (ASD). Despite its incredibly unhip name, ASD performs the miraculous feat of playing MP3 files at a reduced speed while maintaining all pitches. I was completely floored by not only how well the software worked, but that it worked at all. The application reliably slows down everything (vocals, instrumentals, percussion, etc.) by up to 400%, but maintains the pitch of every sound. When you think about what it has to do to achieve this, it is even more amazing. When you slow a sound down, you essentially spread it out in time. In order for every sound wave to keep its pitch (i.e., its shape), the algorithm has to "fill in the blanks". That is, for every frequency present, it has to slip in as many new wave forms of each frequency as necessary in order to fill in any gaps caused by the slowdown. There has to be some pretty clever digital sound processing going on here. I'll bet this algorithm wouldn't have been feasible even a few years back because the computers we had then just weren't fast enough.

I read about ASD one morning during my usual net reading time. In one of those wonderful bits of synchronicity that gives our lives mystery, purpose and a means to thwart the skeptical, that very evening at dinner my son Tim, who is an aspiring guitarist, wistfully wished for some way to play songs slowly. He had been working for days on a particular solo, but had been frustrated by the difficulty of figuring out how to play it. He had the tablature for the song, but just couldn't seem to make his fingers do what needed to be done at the required speed. I gleefully told him of what I had learned. After dinner we downloaded a trial version of ASD to his Mac, and in a matter of a few minutes he was up and plunking on this song, only at quarter speed. With this advantage, he finally was able to master it. After a few days, he decided that he wanted the full version of the software, so he sprung for the $45 to buy it. Although I am not much of a musician, it seems worthwhile to me, and I'd recommend the product highly based on what I saw of his experience.