DHD20230714: better conversion of input filename to tune name.
DHD20230714: tweaking volume down to stay away from red!
DHD20230715: building up expression (a little) for chorus/drop.
DHD20230715: created GenerationParameters.makeDerivedSeed().
DHD20230715: alignment first pass done; partial start/end bars omitted if enough data.
DHD20230726: started building in progression and randomisation, eg random minor scale for house.
DHD20230727: added expression for fade in/out for bass.