Instruct: Classify Amazon reviews into positive or negative sentiment
Query: what have they done?

I had been searching for a clean digital version of this for years. The original LP was in my collection from four decades back and I had digitized it when I made the great shift to MP3 and FLAC years ago --But what have they done to this music? It's not simply the compression. The MP3 I made years ago sounds light years better than this, even though the record was ancient and scratched.