Elizabeth Cree (mezzo-soprano Daniela Mack) makes her confession. (Steven Pisano)

PHILADELPHIA — What do you do when your opera company is doing all kinds of innovative new things but still not getting the audience you think you deserve? Here’s one answer: Put on a huge new festival and fill your entire city with opera. Opera Philadelphia has been planning this for a couple of years: Now, the O17 festival has begun, turning the city into a giant opera stage for 12 days. The company is striking a huge blow for the idea that arts organizations do better to add new, exciting things than to tread with financial caution. The festival is one of the most enjoyable additions to the fall calendar in years; it’s attracting opera fans from all over; and so far, it looks like a success.

I’ve been high on this concept since Opera Philadelphia first broached it two years ago, but there was still plenty of room to belly-flop. Presenting a lot of new work is always risky — the O17 festival includes two world premieres and another piece written this year — and presenting multiple productions at the same time risks compromising production values. I’m happy to report that Philadelphia is doing it absolutely right. It’s offering a good range of work, from the brand new to the tried and true, such as Barrie Kosky’s invigorating production of “The Magic Flute,” already seen in several cities; the silent-film, cartoon/video take on Mozart’s classic appealed both to opera lovers and newbies. (There’s also a free Opera on the Mall performance of “Le Nozze di Figaro” on Saturday night.)

It’s put together a festival that reflects its city. Not only does it draw in venues all over town — David Hertzberg’s “The Wake World,” another world premiere, at the Barnes Foundation; “War Stories,” a double bill including a one-act piece by former Opera Philadelphia composer in residence Lembit Beecher, at the Philadelphia Museum of Art — but there’s even a piece about Philadelphia. “We Shall Not Be Moved,” by Daniel Bernard Roumain, is a multimedia collage about a group of kids who identify as black in inner-city Philadelphia, set in the locale of the 1985 MOVE bombing, during which Philadelphia police dropped a bomb on a residential neighborhood. Roumain’s music is beautiful and somewhat static, noodling along with appealing aching sounds to create a kind of unvaried emotional palette (lovingly conducted by Viswa Subbaraman), but the material was searing, the performances were incredibly strong — including the lyrical countertenor John Holiday as anguished, transgender John Blue; Lauren Whitehead as the gang’s emotional ringleader; and the powerful Kirsten Chávez as the police officer the group takes hostage — and Bill T. Jones’s choreography kept the staging fluid and animated. It was deeply moving.

The sum of these disparate parts was a festival that wasn’t derivative of anything else; it felt very much like its own thing, and seemed, when I was there, almost entirely free of the kinds of first-time struggles that used to plague, for example, the late lamented Castleton Festival. This is what happens with a strong vision and good, thoughtful planning. I’m sure there were plenty of last-minute crises, but they weren’t apparent in the crowd.

The other world premiere was “Elizabeth Cree,” by Kevin Puts and Mark Campbell, the team that brought you “Silent Night,” which won the Pulitzer Prize in 2012. I found “Elizabeth Cree” more engaging and less stiff than “Silent Night”; it’s a Gothic penny dreadful, based on the same true story that inspired the recent film “The Limehouse Golem,” about a series of murders in Victorian England. There’s more than a casual nod to the macabre darkness of “Sweeney Todd” in Campbell’s libretto. Puts doesn’t quite let himself go to write actual show tunes in the music hall scenes, although his music was engaging and lively. The opera opens with the titular heroine — powerfully sung by Daniela Mack — sentenced to death for the murder of her husband; it then flashes back to Elizabeth’s membership in a music-hall troupe, then her marriage, interspersed with a series of grisly and attention-getting murders that touch her life. In opera, it’s the custom to read the libretto before the show, but doing so in this case would spoil the surprise twist at the end. Campbell isn’t great at creating well-rounded characters, but he’s good at fluid lyrics and quickly moving plots, and gave a solid framework for Puts’s vivid music. Add strong conducting by Opera Philadelphia’s music director, Corrado Rovaris, and appealing support by Troy Cook as the complex husband John Cree and Joseph Gaines as the not-quite-fleshed-out music-hall star Dan Leno, and it was a worthwhile show.

As for “The Magic Flute,” it was enchanting and a little exhausting: Conceived as a silent film, with white captions projected on a black ground on the stage in lieu of the spoken dialogue, it gave all the action to video projections while the singers stood almost motionless in designated places on or above the stage. The Queen of the Night (the slender-voiced Olga Pudova) became a giant spider, chasing Pamina (Rachel Sterrenberg) through a nightmare dreamscape; and Tamino, at the start, was fleeing a dragon, his projected legs churning beneath the motionless figure of the tenor Ben Bliss, singing ardently. Since the singers were forced to hold still to make the videos work, their performances seemed a bit straitjacketed to me, and, despite the antic and insistently clever video, the evening got a little long. It’s a quibble that not many people shared. Starting at the festival’s second day, I was getting email in my inbox from readers and colleagues, telling me that I simply had to come and cover it. “Love this Philly festival!” said one Washington-area music lover. He spoke for a lot of people. This festival isn’t replacing Opera Philadelphia’s regular season — another key piece of the puzzle — but it may become a key part of the season for everyone.

The O17 festival continues through Monday.