I think the civ4 modern era music is awful. Does anyone know some suitable classical pieces for modern era (and/or other eras too)?
If you want sth. awesome, search for "Wolfgang Fortner" Violine Concert, it's so difficult, that (I think) only the greatest Violinist on the whole Earth (Gerhard Taschner) could play it.
If you don't like disharmonic Music, you might find pleasure in "Fritz Kreisler's" Music, which is written in the style of former Artists. He composed great Work like "The Devils Trill's" which first was thought to be written by Guiseppe Tartini and "Praeludium and Allegro" which was thought to be written by Pugani, until Kreisler himself admitted, that he actually was the composer.
Actually you do yourself very easy, if you google the recordings of "Gerhard Taschner" if you really want quality, not in the kind that the record itself is recorded with AAA, at Taschners Time CDs did not even exist, but if you can adjust to some noise produced by the bad record-techniques of that time, you can actually hear a Violinist, that has never been reached again till today. He was Concert-Master of the best Orchestra in the World (Berliner Philharmoniker) but left them for a Solo-Carreer, and, he played lots of modern music, i. e. "Paul Hindemidt", "Kreisler", "Pfitzer", "Chatschaturjan" or "Fortner".
EDIT:
Some more Composers that are not really "modern" but also not "old":
Dvorak, Ravel, Brahms.