When Elvis reentered the pop scene after his army stint, he was a tamer presence, in keeping with the easy-listening sound of the early ’60s. Popular music was moving forward cautiously. However, a major change was taking place: the older artists were losing ground. Despite a few hits by mature balladeers like Andy Williams and Steve Lawrence, music aimed at a younger audience dominated the charts like never before.

But the youth sound in 1961 didn’t stray too far from its adult forebears. Bobby Vee, Connie Francis, the Shirelles – they performed with a slightly different beat than that of oldsters like Eddie Fisher, but they were kept on a pretty short leash.

One step forward, one step back, as early ’60s pop stayed mired in a kiddy sound – teen idols like Bobby Vinton, Dion, and Gene Vincent poured the syrup of puppy love. Yet a new sound was brewing: folk music. Peter, Paul & Mary and the Kingston Trio were recording with a fresh feel, which aspired to a greater social conciousness than bubblegum pop.

Sugar-sweet pop-rock continued to be the direction. However, the Beach Boys were playing with a faster beat, folk music was gaining steam, and Little Stevie Wonder found his groove. A new mood was in the air; was something coming?

Pow! The Beatles landed in America, and pop music (and the world) would never be the same. The group’s February 1964 American debut on The Ed Sullivan Show – a national event watched by 73 million people – sparked a new sound in an entire generation of musicians.

The British Invasion conquered America, as the Rolling Stones, Herman’s Hermits, and Petula Clark took chart positions, and Beatlemania grew to epic proportions. Barry McGuire growled “Eve Of Destruction,” foreshadowing the socially conscious rock that would soon arrive.

The presence on the hit charts of “The Ballad of the Green Berets,” a stiffly-sung pean to military specialists in Viet Nam, pointed to the bitter divisions of opinion about a war the public was beginning to turn against. Meanwhile, the Troggs got groovy with “Wild Thing,” the Stones scored with “Paint It Black,” and the success of the Supremes showed Motown to be a vital force.

Plenty of this year’s new sounds were happy and light, like Sonny & Cher’s “The Beat Goes On,” and the Monkees’ “Daydream Believer.” But plenty of its new sounds took on an acid edge, like Jefferson Airplane’s psychedelic “White Rabbit” and the The Doors’ hallucinogenic “Light My Fire.”

By 1968, “the ’60s sound” was in full flower. The Beatles reigned supreme, accompanied by the acid rock of Steppenwolf’s “Magic Carpet Ride” and the pop sophistication of Cream’s “White Room.” Everyone had a message. Even Motown queens the Supremes were now socially conscious, singing “Love Child,” about an illegitimate child and the legacy of poverty.

In August 1969, the Woodstock Music Festival levitated on the power of three days of music, communal love, and psychedelic drugs. Pop music reflected this, with the huge success of the Fifth Dimension’s futuristic “Aquarius” and Donovan’s otherworldly “Atlantis.” Elvis, who had largely been pushed aside by the ’60s sound, sang the socially aware “In The Ghetto.”