Murphy continued as a booking agent until late in 1979 when he met with Gary Morris, then-manager of Australian rock groups
Midnight Oil and
INXS. Morris wanted to focus on Midnight Oil and asked Murphy to look after INXS, Murphy recalled: Nevertheless, by 1980 Murphy had "dissolved his rock agency and became manager of the band". He subsequently hired Gary Grant as the group's touring manager and by 1982 Grant was his business partner at MMA Management. In July that year Murphy had brokered a deal with
Atco Records for INXS after "[he] had made numerous overseas trips setting up contacts". Grant declared that the "direct signing to a US label was one of the crucial elements in INXS's success". In 1983 MMA set up an office in New York and during the next three years either Murphy or Grant spent "10, 11 months of each year there". In late 1984 Melbourne-based alternative rock group,
Models, were considering breaking up, their label
Mushroom Records tempted them with an offer of recording with US producer
Reggie Lucas. INXS encouraged Murphy to sign the group to MMA: under his influence Models pursued a more commercial sound to a radio-friendly format. Models relocated to Sydney and long-term member,
Andrew Duffield, was forced out of the group by Murphy under "controversial circumstances". According to
The Canberra Times Tony Sarno "in the industry [Grant] and his partner [Murphy] are seen as good operators". By April 1986 INXS were "selling records overseas. Lots of them. [Grant] delights in telling how INXS, no, MMA Management as well have calculated success in America. He talks quickly, with an authority bordering on aggression".
Jenny Morris (ex-
The Crocodiles,
QED) told
Stuart Coupe of
The Canberra Times that back in 1985 Murphy "rang up and said, 'Why don't you come on the road with INXS for a couple of weeks and fill in a bit of time' ... I thought I might as well, and that turned into a two years thing that meant I did two world tours with the band". Morris had supplied backing vocals on their April 1984 album,
The Swing, she performed a duet with INXS' lead singer,
Michael Hutchence on their cover version of "
Jackson" (also in April on
Dekadance), and toured with them from 1985. Under the management of Murphy and Grant, INXS went from a Sydney pub band to playing international venues including headlining a show at
Wembley Stadium in July 1991 with 74,000 in attendance. INXS sold more than 30 million albums worldwide. Murphy also assisted in the commercial success of Models, which achieved two hits on the
Kent Music Report Singles Chart in 1985, "
Barbados" (March, No. 2) and "
Out of Mind, Out of Sight" (July, No. 1). During October 1986 Murphy and Grant teamed with fellow managers Jeremy Fabinyi (
Mental as Anything), Mark Pope (
Jimmy Barnes,
Divinyls), and Ken West (
I'm Talking) to stage the
Australian Made series of concerts. The tour performance order was Mental as Anything, I'm Talking,
The Triffids,
The Saints, Divinyls, Models, Barnes and INXS. It began in Hobart in December and visited all state capitals ending in Sydney in late January the following year. Although the tour had been announced with claims of Australian mateship and cooperation, arguments ensued between various band managers over the proposed concert series film. Some bands felt they had been coerced into unfavourable tour contracts. The tour ended in a fracas when Murphy and Fabinyi argued backstage in Sydney and came to blows. In the 1980s Murphy invested in
digital broadcasting and
music sales but also
organic farming. He created a large-scale
free range/
organic chicken operation and ran a business for daily delivery of organic lamb to restaurants around the world. In 1987 Murphy was rated by
BRW magazine as Australian Entrepreneur of the Year. In 1988 he established an independent record label,
rooART, with
Sebastian Chase (of Chase Records) and Justin Van Stom (formerly of MMA).{{cite web | url=http://www.truetone.com.au/truetone-articles/1988/8/26/how-the-minors-created-a-major/ Murphy signed Australian acts to rooArt including Crash Politics,
The Hummingbirds,
Ratcat and
You Am I. In June 1991 Ratcat had simultaneous number-one single, "Don't Go Now", and album,
Blind Love, on the
ARIA charts. In 1992 Murphy signed a deal with
Time Warner Inc. for international distribution. In February 1995 You Am I had a number-one album with
Hi Fi Way. Later rooArt acts included
Wendy Matthews (ex-Models) and
The Screaming Jets which also helped the label become more commercially popular in Australia. In the 1990s, he sold his publishing company, MMA Music, to PolyGram Music Publishing. ==rooART and Petrol Records==