The history of the National Music Museum is also the history of the countless personalities who have accompanied it over the years, gathering collections, looking for suitable places to store them, studying them, always with the goal of putting them on display.
The birth of the museum goes back to 1911, when Michel'angelo Lambertini was appointed by the government to begin the collection of musical instruments, scores and iconographical items scattered in public and religious buildings.
The goal was to create a museum, a project to which Lambertini dedicated himself with great enthusiasm. However, the musicologist quickly noticed a lack of commitment on the part of the government, which forced him to reformulate the museum project with the help of private investors. It was in this context that he turned to António Carvalho Monteiro, also a collector, to acquire the Keil collection that was in danger of leaving the country. Lambertini sold him his own collection and proposed they advance the project together. Carvalho Monteiro agreed and made up some space to accommodate the items in a building in Rua do Alecrim, where Lambertini, Alfredo Keil and Carvalho Monteiro's collections, making up more than 500 items, came together. The Lamas collection (auctioned by his heirs, in 1916), from which some items were bought, stayed out of this deal.
With the deaths of both Carvalho Monteiro and Lambertini, the project to create a museum was postponed. As a result, the collection remained at Rua do Alecrim completely abandoned until 1931, when Tomás Borba, curator of the then Museum and Library of the National Conservatory, rediscovered it. It was Borba who took on the task of acquiring the rest of the collection from Carvalho Monteiro's heirs, which was then transferred to the National Conservatory. Later on, the instruments that had formerly belonged to King Luís and were at the Ajuda Palace, were added to the collection, as well as some items sold during the abandonment period at Rua do Alecrim, acquired in auctions by the National Conservatory.
After 1946, with the reopening of the Conservatory after works in the building, the museum was officially opened, leading to a period of development of the museological perspective and concern for public access.
In the early 70s, the space taken by the museum became necessary for the creation of three new schools at the Conservatory - Dance, Cinema and Art Education. In the hope that it would be possible for the collection of 658 items to have a place of its own, it was transferred, in 1971, to the Pimenta Palace in Campo Grande. It remained there, in precarious conditions, until 1975. That year, João de Freitas Branco, then Secretary of State for Culture, and the Conservatory Music School decided to transfer it again, this time to the National Library, where the musicologist Santiago Kastner began an inventory of the pieces.
During this period there were discussions as to what was the best place to properly store the still growing collection. Several buildings were indicated as possibilities: the Cabral and Ratton Palaces, in Lisbon; the Belém Cultural Centre; the Queluz Palace or the Convent of São Bento da Vitória, in Oporto. None of these went forward.
In 1991, by decision of the Secretary of State for Culture, in response to the wishes of the National Library board, who claimed lack of space, the collection was packed and once again moved, this time to the National Palace of Mafra, where it remained until the opening in Alto dos Moinhos.
On October 1st of 1993, World Music Day, an agreement was signed, under the terms of the patronage law, between the Portuguese Institute of Museums (now DGPC - Directorate General for Cultural Heritage) and the Lisbon Metro, which finally created the necessary conditions to make Lambertini's dream come true. The space was made available in the underground station of Alto dos Moinhos and the National Music Museum opened on 26th July 1994.