TEHRAN (Reuters) - Clad head-to-toe in black -- the international uniform of heavy metal -- Mahyar Dean looks the archetype hard rock guitar hero.
But along with the mandatory Marshall amplifier and out-sized drum kit, his group, Angband, also boasts a couple of goatskin percussion instruments that have been a familiar part of Persian music for centuries.
In a country where western music is banned, Dean is part of Iran's booming underground scene -- making rock, Iranian style.
"We are trying not to get far from our roots, by using Persian percussion," Dean said, pointing out the daf -- a traditional hand-held drum which looks like a super-sized tambourine with metal chains on one side of the skin that add a scratchy, shimmering sound.
But as Iranian as Angband wants to be, it has had to look further afield to get its music released, signing with a German label, Pure Steel Records.
To be produced within Iran, music must be approved by the Ministry of Culture and Guidance, which checks lyrics and music to ensure they conform to the moral standards deemed acceptable in the Islamic Republic.
Classical Persian music and some forms of pop have prospered under the system, but genres like rock and hip-hop have remained almost exclusively underground.
Many Iranian bands do not bother asking for the mandatory government permits to release their music and seek contracts with foreign companies or put their music on websites blocked by the state but still accessible to anyone with a modicum of technical nous.
The 37-year-old founder of Angband plays down the disadvantages of being a rocker in Iran.
"In addition to becoming internationally known, better CD quality is another reason why we want to have our albums on foreign labels," he said, playing with his long wavy hair.
Many Iranian clerics regard western music as haram, forbidden by Islam.
"Haram music has never been halal (religiously permissible) and it will never be," influential cleric Ahmad Khatami said in July, according to the ISNA news agency.
For the conservatives, western music, movies and television are seen as part of a deliberate "soft war" waged by the West to corrupt Iran's youth.
But access to the Internet and illegal satellite television mean western culture is popular among young Iranians, in a country where 70 percent of the population is under 30 and has no real memory of the 1979 Islamic revolution which toppled the U.S.-backed Shah and ushered in an Islamic government.
"Underground music is a mirror of our society's situation... We express in our music the parts of reality that we are not allowed to say," said Ali, a 28-year-old Tehrani who composes rap music.
"This honesty and sense of freedom are why young people are becoming more hungry for banned underground music."
In a home studio in central Tehran, its walls and ceiling covered with insulators to avoid the music being heard outside the apartment, a four-piece rock band "Wednesday Call" is rehearsing.
"Initially we thought that we would be able to obtain permits to release our albums but after (political) conditions changed, it is not even something that crosses our mind anymore," said the band's guitarist, 32-year-old Arin.
In the 1990s, particularly under the two terms of the reformist President Mohammad Khatami, authorities began relaxing restrictions imposed after the revolution. That trend was reversed by hard line President Mahmoud Ahmadinejad who came to power in 2005.
Musicians' struggle against censorship was the subject of a 2009 movie "No One Knows About Persian Cats," which won the Special Jury prize at Cannes but, like the music it depicted, was banned by the Iranian government.
In the film, a young woman singer Negar (Negar Shaghaghi) and her musician boyfriend, Ashkan (Ashkan Koshanejad), buy false passports and visas and emigrate to London to pursue their ambitions.
In real life, too, many Iranian musicians have left the country in order to continue practicing their art.
Singer-songwriter Mohsen Namjoo, dubbed "Iran's Bob Dylan" by the New York Times due to his protest songs, was sentenced to five years' jail in absentia for insulting religious sanctities. Namjoo lives in California but his music is still heard in Iran.
"I love Namjoo's work and I dream that one day he can have a concert in Iran," said Nahal, a 24-year-old private sector employee who downloads all his works.
With 24-hour MTV-style Persian music channels beamed into Iranian homes by satellite, mostly from Los Angeles, home to a huge Iranian émigré community, the state has hit back, not only by cracking down on illegal satellite dishes, but also, according to some media reports, by offering an alternative.
Reformist daily Sharq, quoting a local website, reported that a new music channel, to be called "Iranian" would be launched in the next few month, broadcasting exclusively Iranian music.
"I have heard that the channel will be run by private sector and it will broadcast authorised music of musicians inside the country," said rapper Ali.
"So it will not help Iran's underground music to show itself."
Editing by Sonya Hepinstall