In the northeastern United States, traditional square dances are frequently done to popular songs in addition to, or instead of, jigs and reels. Where this is done, the caller typically sings the calls, substituting dance directions for some of the words of the song but reverting to the original lyrics for the last few measures of each chorus, often encouraging the dancers to sing along. Singing callers normally choose songs that are similar in structure to fiddle tunes—the same number of measures, played at a similar tempo. There are exceptions, however: a waltz such as "Take Me Out to the Ball Game" may be sped up from its original time to a fast time.