Yes, when she uses classical singing tecnique, her voice is quite different compared to her "pop"-tecnique she used with Nightwish, especially on the two latter CDs CC and Once. On the first three Nw-CDs she was rather a beginner in the measures of classical singing and on CC she was actually quite lost while trying her newly developed pop-tecnique which she later mastered well on Once. I don't mean she didn't sound great on those albums, this only concern her technical skill and her advancing in it.
Many people think that she sang better on Oceanborn and on Wishmanster than she did on the latter CDs, but in fact her classical technique on those CDs was so poor that she had to struggle thorugh the recording sessions and she never could perform certain tracks live. She was young and learning church music in the Sibelius Academy, had singing as a side topic, thus not having attended to full time training in classical singing, which she later did in Germany for three years. Obviously they had to correct some minor details in her singign with electronic means in the studio, but it was also Tuomas to blame because he had no clue about her range and limits at the time he composed those songs. AFAIK, on the FWTE-video some parts of her singing were overdubbed later with studio takes because she failed so bad in some parts on the live recording.
Classical singer is considered a learner at least until s/he turns 30 yrs, but the most demanding opera parts like The Queen Of The Night from the "Magic Flute" by Mozart which includes the difficult "Der Hölle Rache"-aria are (almost) never given to be performed by singers under 35 yrs old.
If you have her Christmas album "Henkäys Ikuisuudesta", you can compare the classical tracks "Ave Maria", "Magnificat Quia Respexit", "Varpunen Jouluaamuna" and "Jo Joutuu Ilta" to the rest of the tracks which are sung in pop- or semi-pop technique. The difference is very easy to hear if you turn it up a little.
I've only been to one of her live Christmas concert on the first tour in 2005 when she had more classical oriented repertoire than in 2006. She performed full acoustic in a sold out theater in front of 750 people. What struck me by surprise was the sheer power of her voice. Really, the voice was big and pure, no amps were necessary even the theater was quite big and full of people. Had I never heard classical performances before, I might have been quite amazed. No matter what people say, she has very good classical live voice and she knows how to use it.
Sorry for going offtopic, I'll get me coat.
