Those who hopped aboard the Willie Nelson train once the country music star blew up would surely be shocked to know how not-so-humble looking and sounding his humble beginnings really were.

Willie Nelson Highs & Lows – which debuts Saturday, April 10 at 8 PM ET/PT on REELZ – exposes the musician's fascinating progression from a cookie-cutter Nashville performer to what fans grew to know and love – a laidback and unorthodox singer, songwriter, and performer who ended up also being an actor, activist, four-time husband, and seven-time father.

The Fort Worth, Texas, native is now 87 years old.

At the time, Nelson was quietly and perhaps unknowingly ushering in a new era of music – "The Outlaw Movement" – which was stripped down and authentic, as opposed to lush and overproduced.

But with his new sound came a startlingly new look, courtesy of "a gritty blend of rednecks, hippies and the emerging counterculture" that inhabited Texas at the time. 

And just like that, "his wholesome, polished Nashville look [was] gone forever."

Willie's sounds and image grew more iconic the rawer they both got, which is how he became the poster child for the Texas music scene. 

"They always say Texas was like Christian music, but instead of Jesus, it was Willie, and instead of Holy Water, it was beer, ya know?" quipped country musician Shooter Jennings d