Implement tempo slider in save/load

All we need is:
   Instrument graphics for dropdown
   Dropdown menu arrows
   Updated play/pause images
      Play/pause/clearAll image alignment
   Save filename text box font color:
      Black if white background
      Orange if grey background
   Instrument processing:
      More fade out on trumpet, trombone, and clarinet
      Distorted guitar if possible? (if sounds ok?)
      Possibly shorter note playback since we sped up the tempo