Ahmet Ertegun (, Turkish spelling: Ahmet Ertegun ([ah'met erte'jyn]); (July 31 [O.S. 18 July] 1923 - December 14, 2006) was a Turkish-American businessman, songwriter and philanthropist. He was best known as the co-founder and president of Atlantic Records, and for discovering and championing many leading rhythm and blues and rock musicians. He also wrote classic blues and pop songs, and served as the chairman of the Rock and Roll Hall of Fame and museum, located in Cleveland, Ohio. Ertegun has been described as "one of the most significant figures in the modern recording industry."

A memorial service for Ertegun was held in New York on April 17, 2007. A large part of the evening was given over to musical performances. Wynton Marsalis opened the tribute with the jazz standard "Didn't He Ramble", Eric Clapton and Dr. John performed "Drinkin' Wine Spo-Dee-O-Dee", and other performers included Solomon Burke, Ben E. King, Sam Moore, Stevie Nicks, Crosby, Stills, Nash & Young, and Phil Collins.  Another informal salute to him took place in Los Angeles on July 31, 2007, the anniversary of his birth. The tribute took place at Grauman's Egyptian Theatre in Hollywood. Several of his friends shared anecdotes about their experiences with him and the assembled gathering then saw a special screening of the American Masters documentary Atlantic Records: The House That Ahmet Built. Among those who paid tribute to Ertegun in person were: Solomon Burke, Jerry Leiber & Mike Stoller, Keith Emerson, Peter Asher, Spencer Davis, the film's producer (and longtime friend) Phil Carson, Taylor Hackford and event producer Martin Lewis. Yusuf Islam, formerly known as Cat Stevens, came to America after a 20-year hiatus to attend the ceremonies.  The Martin Scorsese film "Shine a Light" about The Rolling Stones concert held at the Beacon Theatre in New York contains a dedication to Ertegun and Andrea Corr's solo album Ten Feet High is dedicated "To the memory of Ahmet Ertegun".  In honor of the barriers the Ertegun brothers broke during their time in segregated Washington, the current Turkish Ambassador to the U.S., Namik Tan, hosts a series of jazz concerts at the historical residence on Sheridan Circle in Washington, D.C. The "Ertegun Jazz Series," in collaboration with Jazz at Lincoln Center, revives the brothers' legacy of bridging cultures and bringing people together with one common objective: celebrating music. In that same spirit, Ambassador Tan is opening the doors of his home to residents of D.C. from various backgrounds - Members of Congress, Administration officials, academia, the media, business leaders, and others.

Using a quote from the above article, answer the following question: how many attended?