From Woody Guthrie to Eminem, there is a rich tradition of American music inspired by current events. Though one wouldn’t know by listening to the radio, this tradition is alive and incredibly vital — especially in recent albums by composers John Adams and Phil Kline. Adams’ “On the Transmigration of Souls,” commissioned by the New York Philharmonic to memorialize the victims of the Sept. 11 terrorist attacks, recalls the transcendental beauty of Beethoven’s late string quartets. Kline’s “Zippo Songs” is wonderful in a different way: It melds a Schubert-like classical art song with the spirit of beat poetry and antiwar protest.

The noises of “Transmigration” begin imperceptibly: An ambiguous rustling turns into footsteps, a passing taxi — another day in New York. Without warning, a distant scream and a man’s sob. Over this a boy speaks, as if in your ear, “Missing.” Then the chorus softly enters, and you realize that the music has already begun.

This is some of the most tragic and otherworldly music in recent memory, and would be even if its subject matter weren’t Sept. 11. Adams describes the piece, which won the 2003 Pulitzer Prize in music, as a “memory space — a place where you can go and be alone.” Listening to “Transmigration” is an absorbing experience: Elements emerge spectrally over a white-noise background of strings and de-tuned piano. A litany of victims’ names, a short, heartbreaking message from a spouse, more footsteps, this time frantic. It’s like wandering through a diaphanous museum of grief. (Thankfully, Adams doesn’t attempt to narrate the actual events — as he has said, “Nothing could be more distasteful and banal.”)

Musically, the composer, who made his name in the early ’80s as a minimalist, has come a long way from his roots. “Transmigration” brings to mind the rich sonic collages of the symphonist Jan Sibelius or the eclectic Charles Ives more than the repetitive figurations of minimalist Philip Glass and Steve Reich. In fact, “Transmigration” quotes Ives’ most famous work, “The Unanswered Question.” The 25-minute piece is an enormous undertaking, requiring a prerecorded soundtrack of ambient city sounds and voices augments a large orchestra, a 90-person adult chorus and a children’s chorus. Yet most of the time, the music shimmers quietly. Only during its two shattering climaxes, which rival Ives’s fourth symphony in sheer chaos, does the dynamic level even exceed forte.

The texts are drawn from missing persons posters found around New York City. This was a daring choice: The words are hardly poetic, but their straightforward delivery brings out their poignancy. Lines like “He used to call me every day. I’m just waiting” are sung entirely syllabically, often on repeated pitches, a choral acknowledgment that words fail us.

Artists undergo an internal struggle whenever the world around them falls to pieces. There’s an immediate feeling of impotence and self-interrogation, though both can lead to breakthrough. “On the Transmigration of Souls” is comparable to Picasso’s “Guernica” or Hemingway’s “A Farewell to Arms” in its personal reaction to worldwide tragedy, one that is human but unearthly. Though listening to the piece is not necessarily depressing, it raises more questions than it answers.

And what of the musical world since Sept. 11? The New York-based composer Phil Kline has written two brilliant song cycles that scathingly condemn the Bush administration’s post-Sept. 11 offensive. “Three Rumsfeld Songs” takes its texts from the defense secretary’s hilariously roundabout Pentagon briefings. The choice struck me as gimmicky at first, until I realized that lines like “There are also unknown unknowns, / The ones we don’t know / We don’t know” achieve a sort of poetry in their twisted vagueness. The songs are viciously ironic under an absolutely straight face. (I wonder if Rummy himself would even get the joke.)

“Zippo Songs,” also released at the end of last year, features “Three Rumsfeld Songs.” As the name implies, the core of the album is the “Zippo Songs” themselves. The songs’ texts are from another unexpectedly fruitful source: military-issue Zippo lighters from the Vietnam era. Soldiers engraved short sayings or poems on them: “If you got this off my dead ass / I hope it brings you the same luck it brought me.” Inspired, Kline grouped a collection of these engravings together, organized by subject matter. In the composer’s inimitable words, “‘Zippo Songs’ began to take shape as a series of moods and activities, getting bummed, getting high, getting horny, getting bored, dying, finding god.”

Kline straddles many musical styles. “Zippo Songs” is an amalgamation of classical art song, political protest, rock ballad and minimalism. Adding to the confusion is vocalist Theo Bleckman, whose pure, unaffected voice doesn’t seem to follow any vocal convention (no arty vibrato, grungy hoarseness or imprecise slides). It’s the perfect match for Kline’s songwriting, which can start out sounding agreeably like pop, but just as often end up on an unexpected dissonance or jazzy octatonicism.

Though “Zippo Songs” are not expressly about recent events, as “On the Transmigration of Souls” is, it’s not a coincidence that both were written and released during a time in American history of costly military aggression. In a way, that’s what makes the music work — with it comes the realization that not much has changed since the Vietnam War. Both pieces can be heard as pleas to learn from our mistakes.