A year has passed since the morning of the day they did it, and if we’ve learned anything, it’s that we’ll need more than 12 months to absorb the impact of the events that scorched us that Tuesday. One year later, the anniversary of September 11 is generating a flurry of exhibitions, memorials, and benefits, with moods ranging from somber to celebratory.

The first plane struck the World Trade Center tower at 8:46 a.m. EST, and this Wednesday, that moment will be commemorated across the country. In Boston, where the city is planning a full day’s worth of ceremonies and settings for remembrance, Governor Jane Swift will oversee a memorial in front of the State House beginning at 8:30 a.m. (Beacon Street will be closed to auto traffic), with a moment of silence at 8:46 followed by a reading of the names of the 93 Massachusetts residents who died in the attacks. Also at 8:46 a.m., the Central Congregational Church in Jamaica Plain (617-524-2506) will host the Boston Chorus as part of the Rolling Requiem, a worldwide memorial concert beginning in Auckland and Wellington in New Zealand and proceeding hour by hour around the world, marking the time of the first attack with performances of Mozart’s Requiem. Across the river, the city of Cambridge will honor police and fire personnel with a 9 a.m. ceremony at Cambridge City Hall.

All day long, Copley Square will be a locus for reflection; four 140-foot-long platforms will be erected there for passers-by to inscribe hopes and memories. At 11 a.m., Senator Edward M. Kennedy will be among those participating in a memorial service at Faneuil Hall. (For updated information, see www.state.ma.us/mova.) At 7:45 p.m., a candlelight vigil is planned along the Cambridge side of the Charles River, along Memorial Drive between the Larz Anderson and Harvard bridges.

Several area museums are throwing open their doors with free admission and extended hours on September 11. The John F. Kennedy Library and Museum (617-929-4523) will display 10 large panels of the "United in Memory: 9/11 Memorial Quilt," a global undertaking to honor each individual victim with a quilted square; and the Boston Landmarks Orchestra will perform a special concert there at 5:30 p.m. The Museum of Fine Arts (617-369-3300) will hold a day of contemplation with free admission, performances by New England Conservatory musicians, and the highlighting of a dozen works of art relating to feelings of loss and renewal, including Rodin’s Crouching Woman and Duveneck’s Tomb Effigy of Elizabeth Boott. At the American Textile History Museum in Lowell (978-470-0040), 29 quilted remembrances presented to the Pentagon in the aftermath of September 11 are on display through September 13. On September 12, the Isabella Stewart Gardner Museum (617-278-5102) will present "Stepping Through the Ashes," a one-day exhibition of portraits in response to the attacks by Boston photographer Eugene Richards and author Janine Altongy. And beginning next Saturday, September 14, Lincoln’s DeCordova Museum (781-259-8355) will exhibit "Looking at Ground Zero," a group of photographs by Kevin Brubriski.

On September 11, 2001, Roswell Rudd and the Charlie Kolhase Quintet played on at the Regattabar in Cambridge (617-876-7777), providing solace to the shell-shocked jazzheads who joined them; this year, they’re back to commemorate the occasion (see Jon Garelick’s interview with Kohlhase and Rudd in Arts). Elsewhere in clubland, benefit concerts will abound. The Pond in Cambridge (617-661-8828) gets a headstart this Saturday, September 7, with "A Tribute to Fallen Heroes," an 18-band hard-rock extravaganza to benefit the New York Times’ 9/11 Neediest Fund. On September 11, the Comedy Connection in Faneuil Hall (617-248-9700) will brave the solemnity with an evening of funnymen to benefit the Massachusetts 9/11 Fund. Benefits are also planned on Wednesday at the Zeitgeist Gallery (an 8 p.m. jazz/improv show with Oranje and the Mike MacAllister Group to benefit the Cambridge Fire Department; call 617-876-6060), the House of Blues (a "Music for World Peace Benefit Showcase"; call 617-491-BLUE), and Club Passim (proceeds to benefit the Massachusetts 9/11 Fund; call 617-492-7679). At Mama Gaia’s café in Cambridge (617-441-0666), a "Community Open Forum" is presented for anyone to share art, music, and words.

At the Big Easy in the Alley (617-351-7000), they’ll wait until September 12 for "A Year and a Day," an evening of film, music, and art for charity beginning at 5 p.m. And Cambridge’s indie-rock hotspot, the Middle East (617-864-EAST), where even the Fourth of July is an occasion for music, will remain shuttered on September 11 "out of respect and mourning for what happened last year," says owner Nabil Sater. "These are sad times," he repeats in a strained whisper. "These are sad times."