Anyone remotely interested in collecting stamps with the pipe organ theme will be familiar with the famous bamboo organ in Las Pinas, Philippines. Chris van Doodewaard has posted a very helpful article on the organ. The builder was a priest, Father Diego Cera. It was begun in 1816, heard in worship in 1821 and called "complete' in 1824 with the addition of a horizontal trumpet stop. The instrument is made almost entirely using bamboo. The horizontal reed pipes are in fact metal. The organ endured its harsh environment for many years but was finally declared unplayable in 1972, shipped to the Klais firm in Germany in 1973, rebuilt in a climate-controlled facility that replicated its "home" conditions. It was returned and re-installed in 1975. The organ has a single keyboard, divided. It was designed and built in a Spanish style.
The organ is featured on a set of three stamps (Scott 903-905) issued in 1964. The second of the three stamps was surcharged and re-issued (Scott 1055) in 1971. Philatelic materials related to these stamps are abundant. I have accumulated envelops and postcards, first day covers and programs all using these stamps in various combinations.