I feel like the various members of the world of physics don't agree upon what the values of n, harmonics, and overtones line up for STOPPED pipes where f n = nv / 4L According to my physics text book (University Physics Young and Freedman), for stopped pipes, 3rd harmonic = n is 3 = second overtone. HOWEVER, I got a question wrong on my second exam in General Physics because I believe my professor is one of those part of the confusion. I copied and pasted the following from the exam solution: QUESTION:The second harmonic (the second fundamental frequency) of a stopped (closed at one end) organ pipe is 172 Hz, the speed of sound is 344 m/s. How long is the pipe? ANSWER GIVEN BY PROFESSOR: The first harmonic corresponds to L = (wavelength) / 4, the second one to L = (3*wavelength) / 4 When I was doing this problem, I was immediately confused because the question asks for the SECOND harmonic of a STOPPED pipe. According to what I understand, there IS no second harmonic and n goes straight from n = 1 to n = 3. Can some one please explain what is meant by second harmonic for a stopped pipe. Did my teacher screw up?