Accapella stuff

[Proginoskes]

The passion of the performers can't alone circumvent the requirement for a tonal instrument (voice backed only by drums doesn't work either), and whether any given song (indeed, any given arrangement of any given song) will actually generate a power remains uncertain (I'm pretty sure the odds of success depend on how strongly the performance "speaks", which is usually but not always related to its passion), but DHBirr's "hack" should work and a more passionate performance usually maps to a stronger power.