Tandem is a virtuosic composition for two trombones. One of the recurring musical elements in Tandem is microtonal tremolo within glissandi, accompanied by short tones or trills from the second trombone. The piece also offers an optional miniature choreography for the performers and includes a more or less audible quotation of the Slovenian folk song Zeleni Jure. Various opportunities are given for the performers to showcase their technical skills at the fastest possible tempo, for example in overblowing harmonics or playing sequences of scalar passages. A brief, calmer section introduces some acoustic modifications to the instruments and a less conventional playing style.

An extramusical interpretation of the piece might refer to the titular programmatic object—a tandem—hinted at both musically and choreographically, although such a reading is not necessary. The piece concludes with an inverted phrase from the opening bars and ends, metaphorically speaking, with either a full stop—or a flat tire.