The 1st octave fundamentals of electric bass run from about 41 to 82 Hz. However, it is the 2nd harmonic that contains the most sonic energy. That applies to all musical genres that use electric bass, not just to classic rock- which, by the way, didn't get to be called classic for nothing. This RTA is not significantly different from those taken at a concerts by Ja Rule for one, as well as Deep Purple, Ted Nugent, David Lee Roth, Sammy Hagar, Brooks & Dunn, CS& N, Styx, Kansas, a dozen odd new wave acts whose names I don't remember (and in six months no one else will remember them either), and interestingly enough, the Boston Pops. While the gross SPLs of acts varied over a 10dB range the actual frequency content remained relatively constant, with Heavy Metal acts being the only exception, as they tended to have very little midrange content.