Based on my general understanding, I think Popular/Parlor music would have mostly been based on popularized sheet music of the time and would have had the piano as the primary instrument, possibly parlor guitar, violin or some other odds and ends.   However that would have been predominantly in urban and suburban settings or at least homes that were wealthy enough and large enough to have a parlor and/or a piano.   To my understanding steel strings were not regularly used on guitars until the 1890s.   The music in the isolated rural areas would have been quite different, but that was front porch music not parlor music.

I stumbled across an interesting web site on cultural life in mid 19th century Cincinnati that discusses popular/parlor music of the time with some specificity:

http://lcweb2.loc.gov/diglib/ihas/html/ohio/ohio-home.html