Where can I get an idea what these courses are like?

Some courses have public websites, some don’t. If you search the UCI Schedule of Classes (http://websoc.reg.uci.edu/perl/WebSoc) you can find meeting times and website links for any given quarter. You can also browse faculty pages that often list courses, such as:
Prof. Dessen: http://music.arts.uci.edu/faculty/michael-dessen
Prof. Dobrian: http://music.arts.uci.edu/dobrian/courses.htm
Prof. Ligeti: http://music.arts.uci.edu/faculty/lukas-ligeti
Prof. Mitchell: http://music.arts.uci.edu/faculty/nicole-mitchell
Prof. Umezaki: http://music.arts.uci.edu/faculty/kojiro-umezaki