Branch president John King said it had asked ex-services groups not to take younger children on the march after a child tripped during last year's parade causing an elderly man to fall.

Both had needed treatment from paramedics and the incident had been traumatic for the pair, he said.

Children younger than 12 were unable to keep up with other marchers and the RSL branch wanted to prevent injuries, Mr King said.

"I know it doesn't sit well with the general public but that's a fact," he said.

"We're not trying to cut people out of the ceremony, we just ask people to acknowledge this is a fact of life.

"It has been the case where we've had little tykes injured, and to me that's unacceptable."

The RSL branch also asked Scouts, Guides and the Boys' and Girls' brigades to select marchers who could keep up with the parade and hold banners, and the groups had agreed with the changes, Mr King said.

Children under 12 can still form a guard of honour at the entrance to the marching route, and can join Scouts, Guides and the brigades in a march following the main parade.

The branch's public liability insurance had not changed but the RSL needed to lower the risk of injuries to marchers, Mr King said.

An ACT RSL decision will also see Australian Defence Force Academy Band, Salvation Army Band, Canberra City Band and Pipes and Drums not take part in the march down Anzac Parade, despite many decades of involvement.

In a recent letter to bands outlining the decision, obtained by The Canberra Times, Mr King said this year's march would trial an audio system called a "delay stack".

"It will provide a synchronised transmission of the music being performed by the Royal Military College Band from their position on the Australian War Memorial parade ground along the length of Anzac Parade," the letter said.

In the letter, Mr King said the changes to the march came after complaints to the RSL from some veterans.

"For many years there have been issues with the march music, including inconsistent tempos and audibility, that have been of concern to our marching veterans," Mr King said.

"The unfortunate consequence of this change is that [Canberra City Band, Salvation Army, Pipes and Drums and Australian defence Force Academy] will not be required to perform for the marching contingents on Anzac Day this year."

The decision has come as a shock to many of the bands involved in Canberra's Anzac Day commemorations, with some bands providing music for the marches since the 1920s.

Canberra City Band spokesman Stephen Hallyburton said the band was devastated by the news, with the band playing at Anzac Day marches since 1926.

"Obviously this is very sad news for us. We have very little detail about why the RSL has taken this decision, but on the face of it, it does not strike us as very sensible.

"Piping music down Anzac Parade via speakers is not going to create the same atmosphere as live marching bands."

Despite the RSL claiming complaints from marchers was the reason behind the change, Mr Hallyburton said the band was never told of any concerns from those taking part.

"We have never had any correspondence with the RSL about the 'issues' identified in their letter. They came as a surprise to us, as we have always had very positive feedback from the veterans involved in the march," he said.

A spokesman for ADFA said the contribution of the band to events such as the Anzac Day march changes based on plans.

"This year the RSL has chosen a different format that does not include the ADFA band. ADFA will continue to engage with the RSL for opportunities to support events in the future," the spokesman said.

"Anzac Day is an important day in the ADFA program and serves as a poignant reminder to the cadets of the tradition they have inherited from their forebears and the responsibility they have to the nation they serve."

The Salvation Army band was contacted but declined to comment.

ACT RSL chief executive James Davidson said a decision to change music arrangements for this year's Anzac Day was made earlier this year following a meeting with the event's chief marshall.

"The community involvement [of these bands] is not being scrapped, it's just changed," he said.

Mr Davidson said he was confident the changes would work during this year's march.

However, he said there was the possibility they would be revised if it didn't work as intended.