Possible Clues:

• Scorch on the surface
• Bass, possibly, abandoning river for burn
• Burns could start to be vocal like this
• Effect of fire? Someone performing finishes prematurely
• Char needs some cleansing equipment
• Burn slightly on surface
• Warble on a single, burning note?
• Burn; ignes (anag.)
• Burn or char slightly
• Char not quite achieving treble, perhaps