My classroom has a music timeline wall with the different musical time periods. Composers of music that students are studying get added to the appropriate timeline so students have a visual of each composer and his or her place in history. Each time period has a little collage of the architecture, art, fashion, and music of the time. Composers studied in 5th grade are on top; 6th grade is on the bottom. Each time period is color-coded, and each composer poster includes a pictures, dates, country, and title of piece the students are playing. By the end of the year the cupboards are pretty full!
I have more wall space at my other school, so here is the PDF of the larger composer posters and a Word document to add your own composers (scroll down to the bottom to see an example of the finished product). If you're tight on space, here's a much smaller version with just composers from the Orchestra Expressions method book, book one.