I've been looking around the internet (albeit not very energetically) and I can't seem to find the answer to my question:
Is modern classical music defined by its 'unconventional' uses of tonality? Eg. is it possible to write a Neo-Classicist piece in functional harmony, and rely on other elements of the composition to make it modern, or is the use of tonality as a device rather than as a structural element essential?

Sorry this question is so specific! I just thought it'd be easier to ask than to spend my life trawling the web.