Shortly before his death in 1711, Duncombe commissioned an organ for the church, the first to have a swell-box, by Abraham Jordan (father and son). The "Spectator" announced that "Whereas Mr Abraham Jordan, senior and junior, have, with their own hands, joinery excepted, made and erected a very large organ in St Magnus' Church, at the foot of London Bridge, consisting of four sets of keys, one of which is adapted to the art of emitting sounds by swelling notes, which never was in any organ before; this instrument will be publicly opened on Sunday next February 1712, the performance by Mr John Robinson. The above-said Abraham Jordan gives notice to all masters and performers, that he will attend every day next week at the said Church, to accommodate all those gentlemen who shall have a curiosity to hear it".