As a side note, presuming that the DRMed tracks are from iTunes there is away around the problem. If you are a US user, you can sign up for iTunes Match, match the DRMed tracks, download DRM-free versions of the matched DRMed tracks and then cancel your subscription.
I think Apple would charge you for a whole month, so it probably isn't worth it for 20 tracks, but in case anyone else is in the same boat with a larger amount of music...
As another option, you always had the itunes plus option of "upgrading" your tracks to the non-drm versions. I upgraded my last drm purchase about 2 years ago according to the timestamp.
Itunes has been drm free for some time now, drm on music is quite... quaint by now.
I think Apple would charge you for a whole month, so it probably isn't worth it for 20 tracks, but in case anyone else is in the same boat with a larger amount of music...