Only now is '60s Brit songstress Lulu touring the U.S.

A 2007 performance of "To Sir With Love"

Four years after her first appearance there in 2013, and over 50 years since her breakthrough hit cover of the Isley Brothers classic "Shout," British Invasion songstress Lulu returns to New York's B.B. King's on Tuesday night as part of her first-ever string of dates in the U.S. as a headliner.

"I did a couple gigs in America when I was very young, but never really toured there," says Lulu, who was a teenager, when "Shout" reached No. 7 in the U.K. and paved the way for such U.S. hits as the chart-topping 1967 soundtrack theme to the landmark British film drama To Sir, With Love, which she also starred in with Sidney Poitier. Her first B.B. Kings concert was actually her first in New York, and featured a stellar band of seasoned pros including Paul Shaffer and the Fab Faux’s Jimmy Vivino, Will Lee and Rich Pagano.

This time Lulu, who tours heavily at home, has her own band.

"I was invited to do that first show as a one-off with those guys, and it gave me the taste to come back now," says Lulu, who grew up in a Glasgow working class neighborhood. "It's taking me back to where I began in small clubs—and I got a taste for it again at B.B.'s because I do big gigs in the U.K. and Australia, and this is a whole other thing, kind of like closing the circle: I'm not starting over again, but getting back on track, maybe, and reconnecting with my roots."

And even though Lulu never moved to America—let alone toured here—her musical roots are entrenched in American music.

"I love American music and culture and history, even," she says. "My mother was obsessed with American films and wouldn't watch any British ones, and I only listened to American music because British music paled in comparison until the Beatles—and I understood how they were influenced by American music."

For Lulu, it was "anything Ray Charles did, the Stax label, Motown. Anything bluesy with a bit of soul, rock 'n' roll, country--it's all gospel-based. I love any sort of music if it has soul in it."

No surprise, then, that Dusty Springfield was the only female singer in the U.K. that she could relate to.

"It was all about the music—that's what drove me and made me get up in the morning," says Lulu. "I was five-feet-one, with a round, fat face—not an iconic look. They thought I looked lik a lollipop, I suppose—but I didn't sing like a lollipop!"

That would be an understatement, for Lulu was as big in voice as she was small in size—much like America's Brenda Lee. "It was difficult to put the visual and sonic thing together when I was young."

So she doesn't like some of her early hits, which while successful "and good for young teenage girls, were rather lightweight."

She particularly singles out "Boom Bang-a-Bang," which reached No. 2 in the U.K. in 1969 as the country's entry to that year's Eurovision Song Contest, but notes that other songs, like the much-recorded '60s antiwar folk song "Morning Dew" (it famously appeared on the Grateful Dead's 1967 debut album and was a hit for Lulu the following year), were certainly great songs. Also included in this category is Bert Berns' "Here Comes the Night," a 1964 U.K. hit for Lulu before Them, featuring Van Morrison, recorded it and had the far bigger international hit with it in 1965.

"l prefer Van's version!" Lulu admits. "Mine was slow and dreary, which is why it wasn't a bigger hit." And while she minimizes the quality of some of her other early recordings, she credits her producer then, Mickie Most (also hit producer of Herman's Hermits and the Animals), for being skillful at picking hits like the Neil Diamond composition "The Boat That I Row," which she now does in a Tom Petty Americana-type arrangement, and "To Sir With Love."

She notes that E. R. Braithwaite, the Guyanese author of the autobiographical novel on which the film To Sir, With Love was based, died last year at 104.

"He performed a major service in his life in giving it to the world," she says, wondering if maybe she wasn't meant to come tour America now, 50 years later, at a time when another one of her 1964 hits, "I'll Come Running Over" (co-written by Bert Berns) has been soulfully revived by blues guitarist Samantha Fish.

"I was living the dream at home, I suppose," says Lulu, citing her companion career as a television personality as host of several TV series. "It's crazy I didn't move to America, but life takes twists and turns, and my TV shows had so many amazing people like Aretha Franklin, Jimi Hendrix, Wilson Pickett, Tom Jones and on and on. Then I worked with David Bowie [he co-produced and performed on her 1974 covers of his 'The Man Who Sold the World' and 'Watch That Man'] and became a singer-songwriter in my forties [she co-wrote, with her brother Billy Lawrie and Steve DuBerry, Tina Turner's 1993 hit 'I Don't Want Wanna Fight']."

And at the root of it all, she repeats, is soul.

"I can appreciate and respect young artists, but if there's no soul in their essence, I don't love them," she says, naming Bruno Mars as one newcomer who does make the cut. She also notes that she's met a young songwriter who's penned two songs that she "completely" loves for her next studio project, and looks forward to a 45-date tour of the U.K. in the fall, when she'll add a couple more Bert Berns songs to the repertoire.

"I feel that now I've gotten back to where I really belong," she reiterates. "It's taken so long to really tour America, but I've got to do it and not leave it undone. I hope it means I come back more often, but you can't force things. You have to work towards them."