Playing on The Millstone's iPod is Roses from the South, by Johann Strauss (Son). It is still one of my favourite "happy musics".
I had a "waltz phase" about 25 years ago. I could listen to waltzes for hours and let my imagination run wild. Waltz was synonym for imperial, glamorous Vienna, beautiful, romantic Sissi, swirling, carefree fun, dizzying, passionate (but very elegant) emotions.