When Jay Beckenstein was performing in jam sessions in Buffalo, New York back in the 1970's, little did he know that he was in the process of defining a genre of music.

From those jams grew Spyro Gyra, one of the most successful practitioners of the smooth jazz sound on the pop charts.

The latest edition of Spyro Gyra will perform at Penn's Peak in Jim Thorpe Friday evening. Show time is 8 p.m.

The genesis of the group came with those instrumental workouts with Beckenstein and keyboard player Jeremy Wall at a Buffalo club called Jack Daniels. Those informal, improvisational sessions were billed by the club as "Tuesday Night - Jazz Jam".

The club owner pressed Beckenstein for a name of the group to put on his marquee, so Beckenstein reportedly jokingly told him to call the band "spirogira", the scientific name for an algae commonly referred to as pond scum.

The following week, the club marquee billed the band as "Spyro Gyra", misspelling the scientific reference, but the name stuck.

Spyro Gyra's sound is often labeled as smooth jazz, but it incorporates elements of rhythm and blues, latin, Brazilian music and whatever struck its fancy.

In 1979 Spyro Gyra had its commercial breakthrough with its second album, Morning Dance, with its title track reaching the Top 40 on the Hot 100 chart.

The band's success opened the doors for other performances working in a similar vein. Beckenstein's alto saxophone playing was among the vanguard of musicians including Grover Washington, Jr. and David Sanborn.

Spyro Gyra has been a prolific recording ensemble, at one point releasing 20 albums in 20 years. Its latest CD, Down The Wire, came out in 2009. That same year, the band received a Grammy Award for Best Jazz Instrumental Album for 2008's A Night Before Christmas.

According to Billboard magazine, the group has sold over 10 million albums in its 30-plus years together.

Beckenstein and keyboardist Tom Schuman are the only constants in Spyro Gyra's line-up through the years. Schuman joined the band as its second keyboard player; Wall eventually stepped down from the live band, although he stayed on as an assistant producer and songwriter over the years.

In addition to Beckensteim and Schuman, the rest of the current roster includes guitarist Julio Fernandez, bassist Scott Ambush and percussionist Bonny B.

Tickets for Spyro Gyra at Penn's Peak on Friday, April 23 are $28 for premium reserved seating and $23 for regular reserved seating. Tickets are available online at www.ticketmaster.com and all Ticketmaster outlets, including Boscovs and Gallery of Sound stores, and at the Penn's Peak box office and Roadies Restaurant. For more information, call toll free at 866-605-PEAK.