NEW YORK -- Ruben Blades says he never imagined his CD "Tangos" would be nominated for a Latin Grammy.

Instead, it's up for two -- album of the year and best tango album.

"People probably have to rub their eyes and say, 'What, Ruben Blades in the tango category?' I was surprised because you never know about Grammy nominations. My album 'Siembra,' arguably the biggest seller in the history of salsa, never got nominated for a Grammy," said the 66-year-old Blades, who has won four Latin Grammys and six Grammys.

The Panamanian-born Blades says the nominations are affirmation of his belief that re-creating his salsa songs as tangos would work, even though he had to use completely different phrasing in singing such songs as "Paula C," "Ligia Elena," and "Adan Garcia."

At Thursday night's Latin Grammys, Blades will be performing the "Tangos" version of his biggest hit, "Pedro Navaja," inspired by "Mack the Knife," his socially conscious song about the life and death of a murderous street hustler.

On the new album, he performs "Pedro Navaja" with veteran Argentine bandoneonist Leopoldo Federico's orchestra as a milonga, a slightly faster tango style, a far cry from the original version on his 1978 "Siembra" album with Willie Colon, with blaring police sirens and horns and a throbbing salsa beat.

"I felt that the instrumentation and the atmosphere that tango creates would make the lyrics more relevant and stronger," Blades said in a recent interview.

"Salsa is action music, whereas in the tango you have space for reflection. There is something about tango that is very emotional. The instruments -- the violin, the bandoneon -- evoke nostalgia, sadness, opportunities lost and/or found. I always felt that some of my lyrics were shortchanged by the salsa format" with its strong rhythms that got in the way.

Blades and his collaborator, arranger Carlos Franzetti, began discussing the tangos project more than a decade ago, but Blades put his entertainment career on hiatus to serve as Panama's Minister of Tourism from 2004-2009.

Franzetti says the biggest challenge was to dissect Blades' original songs and "mix the elements into a new brew."

"Tango is a completely different genre than salsa: no constant rhythmic pulse, no percussion, different melodies, harmonies and instrumentation," Franzetti said in an email. "I had to apply all these tango elements to Ruben's songs, maintaining their integrity while making them into believable tangos and milongas."

"Tangos" reflects a genre-blending approach to music that Blades has dubbed "mixtura."

Blades will soon be going into the studio to do a "rock en espanol" album, also including some English-language songs he wrote with Lou Reed, with his new Paraiso Road Gang band that he formed with his wife, singer Luba Mason, which he says will play an unpredictable mix from tango and salsa to jazz and bluegrass.

"Mixtura" might also describe Blades' diverse career paths that also include acting and politics.

He resumed his acting career after leaving his government post, taking supporting roles in the Denzel Washington film "Safe House" and the upcoming film "Hands of Stone," a biopic about his friend, Panamanian boxing legend Roberto Duran, starring Venezuelan Edgar Ramirez and Robert De Niro.

Blades says writing songs about social change compelled him to show he cares by taking an active role in Panamanian politics. He's put his entertainment career on hold for several years at a time to get a master's degree in international law from Harvard in the '80s, form his own political party and run for president in the '90s, and then serve as Minister of Tourism.

He's embarking on his final world salsa tour next year and plans to quit performing salsa except in Panama by the end of 2016 and is considering running for president as an independent candidate in 2019 if he feels healthy.

Blades says his political experience -- especially his role in developing Panamanian tourism -- has made him a better person.

"I'm more patient, less selfish and understand things better," said Blades. "The experience has helped me tremendously as an artist because it eliminated a lot of anxieties ... and my spirit is stronger because there's nothing more rewarding than serving your country."