There were people who would have readily agreed with Banjer back in the Civil War days who complained that they were sick of hearing brass band music everywhere they went, but that was "the" popular music of the times. I have heard (not confirmed though) that stringed groups sometimes alternated with brass bands at dances/balls to add variety and give brass players a break. The Frederick Fennell collection (the Civil War, its music and its sounds: copyright 1990 phillips Classic Productions) that DougR mentioned has indeed been reissued on CD and is fun collection: songs-choruses, battle sounds taped in Gettysburg battlefield, brass band tunes, fife and drum tunes, bugle calls, etc. {http://www.amazon.com/exec/obidos/ASIN/B0000057L2/qid=917711858/sr=1-4/002-4232918-4573421}
Also try these CD recordings: (1)string band: Union and Liberty!Music heard on the Northern homefront... by D.C.Hall's New Concert & Quadrill Band (copyright 1994 Dorian Recordings){http://www.amazon.com/exec/obidos/ASIN/B000001QAA/qid%3D917711060/002-4232918-4573421} (2)piano (very nice!) and some vocal: When the Galop Was the Rage by Helen Beedle (copyright 1997 Helen Beedle){was recently available from http://www.americuscd.com ,but does not appear on their online catalog at the moment} (3)brass band: Honor to Our Soldiers by Classical Brass (excellent renditions performed very well on period instruments)(copyright MusicMasters 1991){http://www.amazon.com/exec/obidos/ASIN/B000000FQO/qid%3D917711169/002-4232918-4573421} (4)brass band: Music of the Civil War by The Americus Brass Band {http://www.amazon.com/exec/obidos/ASIN/B0000038IY/qid%3D912178119/sr%3D1-6/002-4232918-4573421}
Finally, a good book reproducing/reprinting actual parlor (piano & voice) music of the war years complete with visually intriguing title sheets: "The Civil War Song Book, Complete Original Sheet Music for 37 Songs" edited by Richard Crawford (copyright 1977 Dover Publications, Inc.) {http://www.amazon.com/exec/obidos/ASIN/0486234223/qid=917712795/sr=1-1/002-4232918-4573421}