The original copy of the Welsh national anthem has been put on display in an exhibition charting Wales' strong relationship with music.
The manuscript was penned by Evan James from Pontypridd
Evan James' manuscript, under its original title Glan Rhondda, dates from 1856. It was later adopted as the national anthem.
Encore!, staged by the National Library of Wales in Aberystwyth, also tells the story behind why the nation became known as the "land of song".
It runs from Tuesday until 29 October.
The words and music for what became better known as Hen Wlad fy Nhadau/Land of My Fathers were composed in January 1856 by Evan James and his son James, from Pontypridd.
The actual story behind the composition of the national anthem is uncertain.
Some believe that Evan James composed the words before his son composed the melody, and others believe that the melody was composed before the words.
STORY OF A SONG
1809: Evan James is born
1833: James James is born
1856: Hen Wlad fy Nhadau composed
1874: Song prominent at national eisteddfod, Bangor
1899: Anthem first recorded in London
The title, Glan Rhondda, which was originally given to the work, was replaced with Hen Wlad fy Nhadau in about 1860.
The song also became the first to be recorded in the Welsh language, when Madge Breese performed it in London on 11 March 1899.
The recording of Hen Wlad Fy Nhadau, for the Gramophone Company, was made on a wax cylinder and lasted for one minute and 17 seconds.
The date of the song's adoption as the national anthem is uncertain but it was given prominence during the national eisteddfod in Bangor in 1874.
Also on display at the exhibition is the oldest example of music for the harp and the earliest form of traditional Welsh music.
A copy of the London Illustrated News from 1873 can be seen too, when Wales was awarded the title of the land of song.
It followed the success of the United Choir of South Wales at a singing competition at Crystal Palace.
The national library spokesman added that one of the most important exhibits was the famous Robert ap Huw manuscript of 1613.
A spokesman said: "This is the earliest manuscript containing Welsh traditional music and the oldest example of music for the harp.
"Part of the manuscript's fame is that it is written in Robert ap Huw's unique notation.
"The manuscript, which was referred to by composers as far from Wales as Vivaldi, has caused heated debate over the centuries as musicians try and decipher the music it contains."
There are also photographs of Ivor Novello, Cerys Matthews, Super Furry Animals, Tom Jones and numerous other past and present stars of Welsh music.