Just the other day we had a guy come into the #banshee channel asking about mandating transcoding of lossless files. At the end of the evening he had written his first ever C# code (prior knowledge of python was stated though) implementing the feature.
Banshee is so much fun to be part of, I personally have very little programming experience but have already managed to get code into Banshee. The existing code base is easy to understand and an absolute pleasure to tinker with. Furthermore the community around Banshee is fun to be part of, very friendly and also always ready to challenge you in unexpected ways.