1. The problem statement, all variables and given/known data Singer sings middle C. She then gulps helium and tries to sing the same note i.e her vocal chords remain the same. What note will the listener hear? 2. Relevant equations f=velocity of air/lambda middle C 3. The attempt at a solution f=velocity of air/lambda middle C gives lambda=330m/s/262Hz=1.2595 After this point im lost i think you have to use freq of helium=velocity of helium/lambda of middle C but what note is that? is it suppose to be C 4 octaves higher or the note G.