Objects/Instances in static classes

I know that you can't instantiate a static class, and all of its members and methods should be static, but I am a little unclear about the use of of other objects within a static class.  Is it legal to make an instance of another class within a static class. example:

static class car()
{
        radio mp3Player = new radio();

        static int SongID()
        {
                int id = mp3Player.getFirstSongId();
        
                return id;
        }
}