For those who love it, it can be a maddening, painful thing to hear how classical music is dismissed by popular culture as relaxing, inoffensive pap. By no means is it high-brow elevator music. Mozart and Beethoven, I’m sorry to say, didn’t sweat and slave over their scores so some kid 200-odd years later could ace his spelling quiz or for some housewife to align her chakras. Even when it cultivates placid, surface beauty for the sake of its own enjoyment, it’s an art that demands active, not passive listening.

Saturday’s program of Bach and Handel with the Pasadena Symphony under its principal guest conductor Nicholas McGegan made for an eloquent case in point.

Both composers have been unfortunate victims of the marketing of classical music as a kind of aural equivalent to New Age healing stones. But these composers’ catalogs number in the hundreds of works, most of them being cranked out to order by their patrons. Their seemingly effortless joy was the product of much physical toil; music that is as much of the mind and soul as it is of the human body – the last detail engagingly delineated by the highly active podium manner of McGegan himself.

Under his baton, the Pasadena Symphony bounded through these works with all the sureness of movement and graceful charm of an Olympic gymnast.

Their partners, soprano Sherezade Panthaki and violinist William Hague, were equal to the task.

Panthaki’s pert and agile voice carved out Handel’s melismatic vocal lines with all the fineness of detail of an etching in silverplate. Hague’s rich tone imbued his performance of the Bach “Violin Concerto No. 3” with a judicious amount of Romantic plush.

On the other extreme of the multitude of musical genres loosely held together under the clumsy rubric of “classical music” is the work of Julius Eastman. On Jan. 23 Monday Evening Concerts dedicated an entire program to the tragically short-lived black gay composer.

No peaceful easy-listening this.

The raw anger of Eastman’s music makes itself heard not only in the composer’s harshly dissonant minimalist idiom, but often in the provocative titles of his works: At the close of the program was a near hour-long work for four pianos starkly entitled “Crazy Nigger.”

A violent and obsessive piece of music that smashed block after granitic block of sound over the listener, it eventually gave way to a beatific coda pealing with disparate voices clashing in wild ecstasy like drunken angels.

The bipartite “Holy Presence of Joan d’Arc,” a lost score posthumously reconstructed from a radio broadcast recording, opened the program with a solo baritone part (dispatched powerfully by Davóne Tines) solemnly intoning a brief text by the composer: “When they question you, speak boldly, Joan. Speak boldly now.” She answered with a voice of 10 cellos: A gnarly 20-minute piece of roiling Klangflächenkomposition based on a rhythmic figure from a Patti Smith song.

Eastman’s was a restless and highly original voice that, sadly, was snuffed out prematurely in 1990 at the age of 49, marginalized and broken in the wilderness of the avant-garde. It’s tempting to hear in his music a presentiment of the often-angry identity politics that have gripped the nation in the last decade. But perhaps it’s not the furious thrashing, the screaming from the edge of the void heard in “Holy Presence of Joan d’Arc” and “Crazy Nigger” that the present ought to take to heart. Rather, it’s their codas that seem to call out to the listener from across the decades; their mad transfigured beauty holding out the hope of a reconciliation that, however painfully wrought, may yet remain within our grasp.

Classical music, be it from the Baroque or from 1980s upstate New York, is a force that still proves to be vital and gripping – even dangerous.