The fourth movement , called Intermezzo interrotto by BartÃ k , has a flowing melody with a time signature which keeps changing . There is also a theme which pokes fun at the march tune in Dmitri Shostakovich 's `` Leningrad '' Symphony ( No. 7 ) . The fourth movement , called Intermezzo interrotto by BartÃ k , consists of a flowing melody with changing time signatures , intermixed with a theme parodying and ridiculing the march tune in Dmitri Shostakovich 's `` Leningrad '' Symphony ( No. 7 ) .