Do some songs require more energy to play than others?

Question

Not based on the length of the song, but on the BPM of some songs would it require more alot more energy to play a Fast hard playing heavy metal song, than it would to play a slower song of the same length???

Answer 1

Certainly the volume level makes a difference as it takes more energy to reproduce louder sounds than softer sounds.  

The beat of a song could have some influence on energy demand. Consider the highly amplified car stereos with the heavy Bass beat music playing(Bass guitar and drums).  (BOOM BOOM BOOM , you can hear them a block away)  Each "Boom" takes energy to produce so it stands to reason that if you play booming bass notes at a faster rate(say 300 in the song) it would take more energy than playing those very same frequency and duration notes but at a slow rate (100 in the song).      

For average stereos and higher frequencies differences in energy usage would be less noticable.  Think how in the nature of music the higher frequency instruments like a guitar can have slower beat notes which are sustained.  In other words Pluck a guitar string and let it vibrate for a lenght  of time.  The vibrations produce a decaying sounds until the next pluck.  There would be a little difference energy wise in a stereo playing a rapid vs slowly plucked guitar as some sound is always produced.  The differences would be in the apparnet volume changes as the string is plucked which make a louder sound.   So the increase in volume of the string as its plucked needs more energy than the quiter sounds it produces as it decays.

To reinforce this concept lets consider some real primitave music that consists of just beating a drum (1 sec duration sustain) at  some BPM and no other sounds produced. We also assume that each drum beat is identical in duration and volume. At 15BPM one drum beat every 4 seconds would require less energy than beating that drum at 30 BPM (once every 2 seconds).    It is during the pause between the drum beats where zero sound is being produced that represents your energy savings.   At 15BPM there is 45 seconds of silence compared to 30 seconds of silence at 30BPM.

With typical music (other than booming bass) you would be hard pressed to measure any meaningful energy differences between music at different beats or tempos. The music notes are sustained and other instruments are playing , there just isn't a pause in sound production that would generate any meaningful energy savings.  

It is more effective to reduce energy requirements of sound reproduction  by lowering the volume than it is to play slower music.