As part of its continuing efforts to improve service — and your videos — YouTube is implementing some significant enhancements to its on-site audio editing package. Aside from a revamping of the general UI, YouTube has worked on its AudioSwap feature, which lets you add music over your video. The audio editing suite now has a slider to aid in finely tuning the mixing levels of music and the original audio, a "featured tracks" area to help with song discovery, and YouTube has also added a ton of royalty-free tracks to choose from, bringing its total to over 150,000. According to the site's official blog, this is only the first in a number of planned changes to its audio editing software. If you want to check it out for yourself, the suite is live on YouTube already, under Video Manager > Edit > Enhancements > Audio.