For the 1999 Venice Biennale, Alÿs created an unofficial performance for the occasion, titled Duett. The piece begins with Alÿs entering Venice by train while fellow Belgian artist Honoré d’O landed at the airport, and each man is carrying one half of a tuba. After drifting through the labyrinth of streets, they eventually met three days later and reassembled the musical instrument. The work is emblematic of Alÿs’s exploration of estranged or misplaced halves striving for reconciliation.