The long: Now, for the sixth winter, Philly's media giant opens its memory-chip-shaped skyscraper's lobby to crowds for a 15-minute, extra-hi-res, wall-projected LED show that puts your TV screen to shame while simultaneously recalling beloved local holiday traditions.

The short: The only free thing you'll get from Comcast this season - or ever.

The demo: All ages. If you're short, arrive 20 minutes early for a spot up front.

The times: On the hour from

10 a.m. to 8 p.m. daily. No show weekdays at 5 p.m., when employees use the lobby to exit.

The dates: Through Jan. 3. (Open Christmas Eve, Christmas Day, New Year's Eve and New Year's Day.)

The show: Elements change from year to year. This go-round, expect more "Nutcracker," as performed by the Pennsylvania Ballet, some drama by Walnut Street Theatre and greatest hits "Carol of the Bells," "Jingle Bell Rock" and "The 12 Days of Christmas."

Get there: Enter on JFK between 17th and 18th streets.

By train: Stop at Suburban Station. You don't even have to walk outside. But you do have to make it past Termini Brothers' stand.

The basics: 1701 JFK Blvd.,

10 a.m.-8 p.m. daily (no show 5 p.m. weekdays), corporate.comcast.com.

Lauren McCutcheon is a Philadelphia-based writer

and mom to a 3-year-old who obeys an elf on his shelf but not his parents.