Music is full of collaborations both perfect and surprising alike. Perhaps most ethereal of them all was the duet between the legendary Ray Charles and Willie Nelson when they serenaded "Seven Spanish Angels" together in the '80s. The song "Seven Spanish Angels" was originally written by Troy Seals and Eddie Setser. Seals has songs recorded by powerhouses like Nancy Sinatra, Hank Williams Jr., Elvis Presley, and more. Seals often worked together with Setser to create some of their biggest hits. But the story behind the Nelson-Charles team-up of "Seven Spanish Angels" is particularly powerful. "Seven Spanish Angels" is a powerful tribute in its own right Two musical angels, Willie Nelson and Ray Charles / YouTube Even before making it to Nelson and Charles, "Seven Spanish Angels" had a mighty pair working on it. The powerful duo of Setser and Seals conceived the song as a tribute to the stylings of Marty Robbins, a celebrated singer, songwriter and even a NASCAR driver. Considered an early pioneer of the outlaw movement, Robbins crooned his way into hearts and ears from the '40s to the '80s to become one of the most popular and successful country and Wester singers of all time. RELATED: Willie Nelson’s Life And Career In Photos As He Turns 90 This origin, steeped in country music royalty, might have been enough, but these two composers made sure the story of the song was worthy of Robbins. Listeners will hear not just powerful vocals and evocative instrumentation - they will also be taken along a narrative of hope and heartbreak, as an outlaw and his beloved flee forces that would see them fall. They do fall - but when they do, they do so together. When singing a song is an artform that requires many skills Marty Robbins, ca. 1970s / Everett Collection Anyone with formal singing experience knows that true vocal training is a very involved process that gets many parts of the body involved and has the singer exercise their diaphragm, master certain postures, and even master the art of breathing - all of these are incredible important to a singer. ANGELS SING, Willie Nelson, 2013. ph: Joaquin Avellan/©Lionsgate/courtesy Everett Collection Nelson and Charles display a capability that encompasses all of these fine requirements and then some; they have mastered their art right down to the skill of effective storytelling. Indeed, the song itself is a narrative, and for how good their voices sound, both singers also make sure they deliver each line to leave the greatest impact and to suit whatever scene or emotion is being set up. On top of all this, the two genuinely play well off of each other, not competing but truly collaborating to make something otherworldly, the likes of which has not and will not be heard again, since its debut as a single on Charles' 1984 album Friendship and Nelson's 1985 compilation album, Half Nelson. Ray Charles, 1988Charles Bush/Courtesy Everett Collection These two set a very firm foundation for this moving song, cementing its place as something to be treasured and sung for decades to come. It's no wonder the song stayed at number one for a week and a total of twelve weeks on the country chart - or that it became Charles' most successful of his eight hits on the country charts. Give it a listen in the video below.