Depends on the tone, pitch, etc. of the voice. If you sing like Finntroll or Children of Bodom you might be singing a church hymn or a children's lullaby, it's still going to be horrible. Sing them same softly (always in an unintelligible tongue) and you get a soothing effect. Goes to show how hard translation can actually be. At least, I'm not studying any tonal languages.
Anything trying to translate from Finnish to English seems doomed to fail. Almighty Google messes up on, for example, 'on sun'. If mina=I and sina=you, and then mun=my, then… sun=your, right? But no. The bloody thing insists on translating 'noun on sun' as 'noun is the sun'. Even though it has 'auringo' as the translation for 'sun'. Aaarrgghghh!!! *brain asplode* Do you get the same IRL? I do when people come to me trying to get me to explain why this or that doesn't work in Spanish.