 Whedon spent six months writing the music for " Once More , with Feeling " . When he returned after the end of the fifth season , he presented Davies with a script and CD , complete with notated and orchestrated music , which Davies found " mind @-@ boggling " . The actors were initially bewildered ; in 2012 , James Marsters commented that " it 's obvious now that they were good songs but the thing was Joss and his wife Kai , they don 't sing very well . And they don 't play piano very well . The songs sounded really cheesy and horrible ... We were saying , ' Joss , you 're ruining our careers . ' " 
