In addition to being a synonym for Contra Bourdon, the name Grand Bourdon has been used for a large pedal mixture, supporting the 32' harmonic series. It is, essentially, a form of Acoustic Bass. According to Locher, the earliest known example was made by Walcker of Ludwigsburg for Ulm, Münster, Germany in 1856, consisting of five Diapason ranks at 16', 10-2/3', 8', 6-2/5', and 4'. In practice, some or all of the ranks of this mixture may be borrowed from other stops.
Of the ten examples of Grand Bourdon listed in Osiris, four are known to be simply 16' or 32' Bourdons and four are known to be compound stops.
Grand Bourdon 32', Pedal; Votivkirche, Vienna, Austria; Walcker 1878. This example simultaneously draws five stops which are also available independently: Bourdon 16', Quintbass 10-2/3', Octav 8', Terzbass 6-2/5'. and Octav 4'.
Grand Bourdon V, Pedal; Cathedral, Riga, Latvia; Walcker 1883. This example simultaneously draws five stops which are also available independently: Octavbass 16', Quintbass 10-2/3', Octavbass 8', Terzbass 6-2/5', and Octavbass 4'.
Grand Bourdon 32' (resultant, composition unknown), Pedal; Sacred Heart Co-Cathedral, Houston, Texas, USA; Pilcher 1922.
Grand Bourdon 32', (resultant, composition unknown), Pedal; Sacred Heart Cathedral, Davenport, Iowa, USA; Noack 1992.