Jukka Nevalainen joined to play the drums and they switched the acoustic guitar for the electric guitar . In May 1997 , Nightwish signed a contract with Spinefarm Records and released their first album ` Angels Fall First ' . In early 1997 , following the release of the Nightwish demo , Jukka â Juliusâ Nevalainen joined the band , and acoustic guitar was replaced with electric guitar .