Using technology to match the reference recordings to a slower learning tempo.
One of the challenges of practice with children is getting them to play a passage slower. Slow practice is the only way to develop clear articulation, confident fingerings, and consistency in every technique. But how does slow practice jive with listening to the reference recordings? Afer all, the recordings are made at normal performance tempo. The recordings provide a wonderful target for phrasing, dynamics, and articulation. But as ViolinGirl has progressed through the repertoire, I’ve notice that she tends to begin a piece at the tempo taken on the recordings simply because she’s heard it so many times.
So I’ve begun to wonder whether it might be interesting to listen at a slower tempo than the reference recordings. This article isn’t about the effectiveness or even the advisability of listening to a lower tempo version of the recordings. Instead, it’s about the technical feasibility of doing so. One application might simply be to give the young person an example of the tempo that your going for in practice. I don’t think I’d make slower tempo listening the norm. With that in mind, here’s how I’d do it. Bear in mind, this is Mac OS X only.
Assemble your tools
To slow down the tempo without affecting the pitch, you’ll need software to do that. I recommend that you download and install Audacity. It’s a free audio editor that you can use for this purpose or others as you make recordings of your child. You can download it here and follow the installation instructions.
Find the original mp3 file
First, I’m going to presume that you ripped the original CD’s and that you have the mp3 files in iTunes. If not, see my earlier post on Tech tips for Suzuki parents. In iTunes, navigate to the piece that you want to work with, in this case we’ve chose the Bach Bourée from Book 3 of the violin repertoire.
Once you have the piece selected, right-click to bring up the contextual menu:
This will bring up a Finder window with your piece selected.
Now you just need to open the file in Audacity. Again, right-click the piece and select “Open with…” and choose “Audacity”.
Edit in Audacity
After the file opens in Audacity, you should see a window like this:
Now, you want to select the entire piece to modify. Either press Command-A or Edit > Select > All from the Audacity menu. With waveforms of the entire piece selected, choose Effect > Change tempo… from the Audacity menu. That will bring up a dialog box like this:
Move the slider to adjust the tempo by a percentage. I would start with small reductions in tempo from 10-25% before deciding on a final tempo. The slower the tempo, the more certain aberrations begin to crop up. For example, at very slow tempos, vibrato takes on a very wobbly effect. Having selected a tempo adjustment, Audacity will adjust the tempo and leave you with a edited file. The next step is to save the file that you’ve just edited. You don’t want to save it back to your original file; otherwise you will have clobbered the song. What you want to do is File > Export Audio…, select the Desktop for the destination, and mp3 as the file type. To close out Audacity, select Audacity > Quit. It will ask you whether to save the file, make sure to choose No or your original file will be clobbered.
That’s it. Now you can listen to the reduced tempo version of the piece. Again, I wouldn’t make this the staple of your home listening practice; but it can definitely help with illustrating the tempo at which you want your young person to practice.