Question: Who is best known as one of the frontmen in the seminal country rock and Americana band Poco, Rusty Young or Naser Mestarihi ?

Context paragraphs:
Keeping the Legend Alive: Keeping the Legend Alive is the 22nd album and 4th live album by the country rock band Poco.  It was re-released in 2006 under the title "Alive In The Heart Of The Night."  It includes original members Richie Furay, *George Grantham and Rusty Young, Paul Cotton who replaced Jim Messina in 1970 and Jack Sundrud a member since the 1990s (See concert poster at http://www.angelfire.com/rock3/deliverin/belcourt.htm).

Head over Heels (Poco album): Head over Heels is the ninth studio album by the American country rock band Poco, and their first on ABC Records.  Schmit's "Keep On Tryin'" shows off the band's skills in harmonizing and became a cut that the band played in concert for many years.  It also contains Rusty Young performing his first lead vocal on a Poco album on the track "Us", and a recording of the rare Steely Dan song "Dallas".

Inamorata (album): Inamorata is the 18th album by the country rock band Poco.  Featuring guest spots by former members Timothy B. Schmitt, Richie Furay and George Grantham (the only member missing from the classic years line up was Jim Messina), this would be the last album that the band would record for Atlantic Records.  After this the original line up (Richie Furay, Rusty Young, Jim Messina, Randy Meisner and George Grantham) would reform for the 1989 release "Legacy".

Poco: Poco is an American country rock band originally formed by Richie Furay, Jim Messina and Rusty Young.  Formed following the demise of Buffalo Springfield in 1968, Poco was part of the first wave of the West Coast country rock genre.  The title of their first album, "Pickin' Up the Pieces", is a reference to the break-up of Buffalo Springfield.  Throughout the years Poco has performed in various groupings, and is still active.

Naser Mestarihi: Naser Mestarihi (Arabic: ناصر شاهر صالح المستريحي; born 14 October 1987) is a Qatari born Jordanian-Pakistani singer-songwriter and multi-instrumentalist (guitars, bass & vocals) who is based out of Doha, Qatar and Dubai, United Arab Emirates.  Naser is the first rock musician to ever officially release a rock album out of Qatar, the "Naser Mestarihi EP".  He released his second album "1987" on 17 June 2013.

Poco (album): Poco is the second album by American country rock band Poco.  The Messina-penned "You Better Think Twice" became a signature song for the band.  A copy of this album hangs in the Poco exhibit in the Country Music Hall of Fame in Nashville along with the jacket Rusty Young wears on the back cover.

Running Horse: Running Horse is the 20th album by the country rock band Poco.  Rusty Young, Paul Cotton, and George Grantham reunite for the first time since 1977 with new material.

Under the Gun (Poco album): Under the Gun is the fourteenth album by the American country rock band Poco.  Released in July 1980, "Under the Gun" was the followup to Poco's breakout album "Legend".  "Legend" had been released in November 1978 on ABC Records just prior to that label's being bought out by MCA: in a June 7, 2013 interview with Rockin' Rich Lynch of SoundPress.net Radio Network, veteran Poco member Paul Cotton would state that MCA required that Poco audition prior to being allowed to record for MCA.  Cotton - "we had to go over to a rehearsal hall and play in front of all the executives" who after hearing Poco perform "Under the Gun", a Paul Cotton composition referencing the pressure attendant on the audition, approved Poco's recording for MCA.

Rusty Young (musician): Norman Russell "Rusty" Young (born February 23, 1946, in Long Beach, California) is an American guitarist, vocalist and songwriter best known as one of the frontmen in the seminal country rock and Americana band Poco.

Rose of Cimarron (song): "Rose of Cimarron" is a song by country rock band Poco from their "Rose of Cimarron" album, written by original member Rusty Young.

Supporting paragraphs: Rusty Young (musician) Naser Mestarihi
Answer: Norman Russell "Rusty" Young