It’s almost impossible to believe that Jethro Tull started out as an R&B-Blues band.

The band on This Was bears no resemblance whatsoever to the band on Thick As a Brick or Songs from the Wood. Tull began life as a slightly quirky group engaged in the enhancement of standard blues-rock numbers through the medium of a ferociously blown flute. Although Ian Anderson was out front in his soon-to-be iconic single-leg pose, lead guitarist Mick Abrahams contributed equally to the repertoire on that first album. There are some solid cuts on This Was, like “My Sunday Feeling,” “Some Day the Sun Won’t Shine for You” and Abrahams’ “Move on Alone,” the latter enhanced with a small horn combo. Abrahams would indeed move on to form Bloodwyn Pig and pursue his blues-rock passion, allowing Tull to become Ian Anderson’s creative vehicle that he would drive in directions no one could have possibly foreseen at the time.

Even harder to believe is that Tull initially replaced Abrahams with Tommy Iommi, later of Black Sabbath fame. Thank God that quickie marriage didn’t last, because who can imagine Jethro Tull without Martin Barre?

Though Martin had a middling resume when he applied for the job, he turned out to be the perfect guitarist for the multitudinous directions the band would take, beginning with Stand Up. A cornucopia of delights, Stand Up is remarkable for creating synergy between vastly different musical styles: blues, rock, classical, Celtic, and folk. There are heavy rockers, erotic blues numbers, lovely ballads and songs that defy simple categorization. In some hands, such diversity might sound like a hopeless tangle of experimentation, but in Tull’s hands, it works like magic. Stand Up is the album that identified Jethro Tull as a major force, and remains one of the truly great albums from a great era in music.

The opening song heralds both continuity and liberation. The opening passage of “A New Day Yesterday” is certainly reminiscent of the music that filled This Was but with a much heavier feel due to the pronounced attack coming from Martin Barre’s Les Paul. I read somewhere that Martin used super-heavy picks in his early playing days, an excellent choice for a style that is designed to balance the maximum impact of every note with due attention to precision. Yes, it’s “A New Day Yesterday,” and that new day appears to signify that Tull is going to power up the sound.

But hold that thought! Out of the blue comes “Jeffrey Goes to Leicester Square,” a song as far away from blues-rock as you can get. The varied influences in this song mark it as the first in the genre of “Tull Song.” As the blogger known as “the Sententious Vaunter” explained in his piece on Stand Up, “Categorizing Tull is like trying to tell what color a chameleon originally was . . .” He goes on to describe this song far better than I can:

And then, of course, there’s “Jeffrey Goes to Leicester Square,” such a genre-bending cavalcade of flutes, bongos, triangles, bass, and guitar, assembled so jauntily and so lusciously, with such rhythm and grace and ease of listening, that I’m not going to tell you about it here.

As if that weren’t a sufficient announcement that Tull is going to be hard to categorize (one of the many reasons why I adore them), Ian Anderson then takes a turn at Bach, rearranging the Bourée in E minor into a jazz-tinged showpiece for his vocalization-peppered flute style. But let’s also give credit here to Glenn Cornick on bass and Clive Bunker on drums, who make a marvelous transition from traditional blues band rhythm contributions to movement requiring more fluidity, flexibility and touch.

Ian Anderson wrote a great deal about family relations during the early years of Tull; you’ll hear the theme on Benefit (“Son”), Aqualung (“Cheap Day Return”) and Thick as a Brick (the sections “The Poet and the Painter” and “What Do You Do When the Old Man’s Gone?”). In the song “Back to the Family,” he expresses the longing we have for whatever we lack, in this case, the dichotomy between home-and-family and independent city life. Using some very clever mood mirroring, the lyrics in the quieter parts express the yearning for one or the other, while the explosive parts express the frustration of dealing with both family (first passage) and the constant demands of life and pushy people in the city (second passage). While at first it’s, “Oh, I’m going back to the family/I’ve had about all I can take,” that perspective changes to biting frustration at the realization that while the family can comfort one through simple familiarity, hanging out with them can be a fucking drag:

Master’s in the counting house, counting all his money
Sister’s sitting by the mirror, she thinks her hair looks funny,
And here am I thinking to myself just wondering what things to do.

So it’s back to the city, which soon yields the response, “What the hell was I thinking?” The song ends in a barrage of rapid-fire flute, speedy bass runs and a glorious guitar solo; it sounds as if the entire band is releasing the pent-up frustration expressed in the song.

Of another style entirely, “Look into the Sun” is a lovely acoustic number, somewhat folk-sounding but with a chord structure more suited to rock. Martin’s electric guitar touches in the counterpoint are well-suited for the song’s style, and Ian Anderson proves he’s quite an accomplished acoustic guitar player. Shifting back to the early Tull sound, “Nothing Is Easy” is a snappy number that allows Ian and Martin to play off each other, trading off riffs and runs in the extended instrumental sections. It’s just a fun frigging song, and Clive Bunker makes it all work with a drum part that keeps the whole thing moving.

The mandolin is rarely used in rock music, and there’s a good reason for that: its relatively thin sound is much more suited to folk, traditional and bluegrass styles. I think the last time I heard it used effectively in rock was on Firstnighter by Acoustic Disturbance, in the haunting, “Waiting at the Window,” where it’s paired with a Ric. The New Pornographers also used the mandolin in spots on a couple of songs on Challengers. On “Fat Man,” the mandolin remains center stage, supported by bongos, tambourine and flute echoes, all very carefully arranged and panned with perfection. I don’t know what was going through Ian Anderson’s mind when he wrote this song, but it’s one of his most playful moments and always makes me laugh.

The bittersweet majesty of “We Used to Know” adds yet another dimension to this new version of Jethro Tull. The song begins with a barely audible passage reflecting the mood of the narrator . . . he’s having a hard time getting the words out. As the song proceeds, the volume rises and the narrator sings with more confidence and feeling. The final verses express an unusual combination of confused feelings: bitterness at the thought of mortality, acceptance of human separation and the realization that shared experience is what makes life worthwhile:

Saving up the birds in hand
While in the bush the others land.
Take what we can before the man
Says it’s time to go.
Each to his own way I’ll go mine.
Best of luck in what you find.
But for your own sake remember times
We used to know.

As time progressed, Ian Anderson’s lyrics became more and more opaque, but here, the lyrics are more direct and to the point. This lyrical clarity is apparent in one of his relatively few love songs, “Reasons for Waiting.” Certainly as strong as any of The Beatles’ contributions to the form, the poetry in this achingly beautiful number, enhanced by strings and soft flute, is sensuous, sincere and memorable:

What a reason for waiting and dreaming of dreams
So here’s hoping you’ve faith in impossible schemes
That are born on the sigh of the wind blowing by
While the dimming light brings the end to a night of loving.

The beauty of this number is breathtaking, but not the last message Tull wanted to leave to the fans of the time. Instead, the album ends with Tull at full throttle in the bashing number, “For a Thousand Mothers,” with a rhythm best described as hard-rock-cha-cha. Another ode to the family, this one is more in the mode of youth rebellion, not through guns and bombs, but through music:

Did you hear mother?
Saying I’m wrong but I know I’m right.
Did you hear father?
Calling my name into the night?
Saying I’ll never be what I am now,
Telling me I’ll never find what I’ve already found.
It was they who were wrong . . . and for them, here’s a song.

There are times during “For a Thousand Mothers” when I think Ian is going to blow his brains out through that flute; the intensity of this song is unique even for him. That intensity reminds us that Stand Up! is another one of those blessed moments of creative liberation, like Dave Grohl’s moment in The Colour in the Shape. Ian Anderson’s message here is: “We refuse to be classified!” In a world where everyone is constantly trying to fit into one box or another, that is a message of jubilant revolution.