The 19-year-old placed fifth at the eighth International Queen Fabiola Carillon Contest in Mechelen, Belgium when it was held in July, an event thought to be the Olympics of carillon playing.

And on Sunday the task of giving the final concert at the carillon on Aspen Island before a seven-month closure has fallen to him.

The concert will celebrate Bray's ascension to the rank of senior carillonist and his success in Belgium, with 600 people expected to cross onto the island to hear the music.

An upcoming maintenance period will see two new bells added, including a G bell weighing more than 5 tonne and an almost miniature D bell, in time for the carillon's 50th anniversary in April, the National Capital Authority has said.

Officials at the authority and Canberra's community of carrilonists had nervously waited for news on the new bell, which has been cast in the ground. They recently received word that the process was a success, breathing a collective sigh of relief.

Bray, who is studying at the Australian National University's school of music, said it was difficult to go past a carillon as a musician.

"It's a huge tower in the middle of the lake ... the biggest bell is six tonnes! What instrument is that big?" he said, taking in the view across central Canberra from the floor where the carillon is played.

Bray's Sunday concert will feature music written especially for carillon that demonstrates the emotive power of the instrument. It is the same repertoire Bray performed in Belgium to show his technical skill with the instrument.

There was still plenty of music being composed for carillon and Bray said he would perform one of his own compositions for carillon, flute and violin - which he was also learning - sometime next year.

The National Carillon's English-made bells - the instrument was a gift from the British government - ring out beautifully with a far richer resonance compared to other European instruments, Bray said.

Bray has been invited to play in Russia and America and will again return to Belgium, after making the finals at the International Queen Fabiola Carillon Contest.

He was the second Australian to play in the competition, which started in 1987, after taking up the instrument four years ago when he was still in high school.

The authority will also complete upgrades on Aspen Island, which will be closed from Monday, September 9 and completed by early April next year.

The National Carillon's Westminster chimes will also be silent in this period.

Peter Bray's 45-minute Sunday carillon concert will be held from 12.30pm.