I don't know if it does this already (I don't think so). Calculating Replay and Album Gain in any music management software can be a bit hit and miss and individual or selections of tracks may need adjustment to make them louder or quieter so they have a better "sound fit" in a playlist. You can already alter the Tag Gain values on an an invidual basis, but the process is a bit cumbersome. It would be nice (for me anyway) to have an option where you could easily select a track or a selection of tracks and get the program to increase or decrease the replay and/or album gain values by a set amount e.g. select tracks a, c, d g and h which have replay gains of -6, -5, -6, -4 and -2 and say "add +3" to these values so they become -3, -2, -3, -1 and +1 respectively.