He also collaborated with Duy Trac on the program Tieng hat sinh vien (Students' voice).

Nguyen Anh 9 started his songwriting career in a very accidental way when touring Japan with Khánh Ly.

He was waiting at the elevator with Khanh Ly to return to his hotel room after the show at Osaka fair.

"Không" became one of the signature songs of Elvis Phương's singing career, as well as some other Nguyen Anh 9's songs such as "Ai đưa em về" (Who takes you home), "Chia phôi" (Parting), "Một lời cuối cho em" (One last word for you),... frequently performed by Elvis Phương on the stage of Queen Bee discothèque in Saigon in early 1970s.

At the same time, he wrote some other famous songs like "Mùa thu cánh nâu" (Brown-winged autumn), "Đêm tình yêu" (Night of love).

After the Fall of Saigon to the northern Vietnamese communists in April 1975, at first he toured the provinces with Duy Khánh's troupe and the songwriter Quoc Dung.

On May 27, 2006, Thúy Nga Productions put on the live variety show Paris by Night 83 with the theme Những khúc hát ân tình (Songs of affection) in California, USA to pay tribute to three Vietnamese songwriters during which the singers performed 11 songs by Nguyen Anh 9.

On the night of November 21, 2010, the program Con đường âm nhạc (The music path) of November paying tribute to Nguyen Anh 9 took place at the Military Theatre, Ho Chi Minh City and was broadcast live on VTV3.

[1] After bearing pneumonia and heart failure for a long time, he went into a coma and died at Ho Chi Minh City University of Medicine and Pharmacy Hospital at 14:00 April 14, 2016, aged 76.