Москвичей предупредили о резком похолодании09:45
Coast route crowned Britain's favourite path。新收录的资料是该领域的重要参考
WINNER: Michelle Williams, Dying For Sex，推荐阅读新收录的资料获取更多信息
The second harmonic is the one you get from the string vibrating in halves. Each half of the string vibrates at twice the frequency of the whole string. The 2:1 relationship between the pitches of the first and second harmonics is called an octave. (I know that the word suggests the number eight, not the number two. Don’t worry about it.) The pitch that’s an octave above middle C has a frequency of 2 Hz, and it is also called C. Both of these notes have the same letter name because in Western convention, notes an octave apart from each other are considered to be “the same note“. The important concept here is that you can move up an octave from any pitch by doubling its frequency. You can also move down an octave from any pitch by halving its frequency.