Protest singer Billy Bragg has helped reverse a government ban on steel-strung guitars in prison.
The activist joined politicians and fellow musicians, including former Smiths guitarist Johnny Marr, calling for inmates to be granted use of guitars with steel strings as well as nylon - the latter being used primarily for classical and Spanish styles.
Bragg, who started the Jail Guitar Doors initiative in 2007 as means of helping prisoner rehabilitation through sourcing guitars for prisons, said: "As an incentive to engage in rehabilitation, individual access to steel-strung guitars can really help the atmosphere on a prison wing.
"I've had a number of projects involving guitars on hold which now will be able to go ahead, and will allow those using music in prisons to get on with this important work."
Labour MP Kevin Brennan (Cardiff West), who also supported the campaign, said: " This is a victory for common sense and I'm pleased after months of campaigning the UK Government has listened. The power of music to help prisoners to rehabilitate is well documented.
"I started the campaign after prisoners wrote to me explaining how they had saved from their small prison wages to buy guitars and how therapeutic learning to play the guitar had been for them before the ban.
"If we want to reduce reoffending we need to support purposeful activities like learning to play an instrument."
Prisoners cannot bring in their own guitars but can buy an acoustic guitar with their own money, depending on the level of privileges they are allowed and subject to each prison governor's discretion.
A Ministry of Justice spokesman said: "Following feedback from prison governors, we have made a few minor adjustments to the property prisoners are allowed to have. These are still subject to individual risk assessments and can be refused by governors.
"As a result of this government's reforms, prisoners are now expected to engage with their rehabilitation and comply with the regime. Those who don't will have privileges withdrawn."
The Prison Reform Trust welcomed the government's decision and the increased use of governors' discretion.
Its director Juliet Lyon said: "It would help if ministers spent less time on operational detail, imposing mean and petty rules, and more on ensuring that there are enough staff, opportunities for constructive work and proper rehabilitation to reduce re-offending on release."