“Doing Business in a GAFA World,” a presentation by Marc Willson on Google, Apple, Facebook, Amazon and other “Internet must-haves” for retail stores and restaurants. Sponsored by the Loudoun Small Business Development Center. 8-10:30 a.m., Mason Enterprise Center, 202 Church St. SE, Leesburg. $30; online registration, $25. www.loudounsbdc.org.
Rotary Club of Ashburn, noon,1757 Golf Club, 45120 Waxpool Rd., Dulles. 703-969-3070 or www.rotaryclubofashburnva.org.
Pinochle, 12:30 p.m., Leesburg Senior Center, 102 North St. 703-737-8039.
Poker, 1:30-4 p.m. Tuesdays and Thursdays, Senior Center at Cascades, 21060 Whitfield Pl., Potomac Falls. $1; center members, free. 703-430-2397.
Karate and self-defense course, for ages 5-12, offered from 3-4 p.m. Thursdays, through March 7. Middleburg Community Center, 300 W. Washington St., Middleburg. $12 per session. 540-687-6375.
Sterling Ruritan Club bingo, benefits local charities. 7 p.m.,183 Ruritan Rd., Sterling. 703-444-6039.
Knitting and crocheting, 10 a.m.-noon, Senior Center at Cascades, 21060 Whitfield Pl., Potomac Falls. Free. 703-430-2397.
Bluegrass, Celtic and folk music jam, benefit for Genesis International; food and beverages sold, including a barbecue dinner from Savoir Fare. 6 p.m.-midnight, Old Furniture Factory, 6 W. Loudoun St., Round Hill. Suggested donation, $5. 540-338-5050 or www.theoldfurniturefactory.com.
After-hours teen center, ages 12-18. Teens must have a permission slip signed by a parent or guardian on file. 7-10 p.m., Cascades Library, 21030 Whitfield Pl., Potomac Falls. Free. 703-444-3228.
“Danny Knicely’s Winter Concert,” Nate Leath, Aaron Olwell, Matthew Olwell, Dan Rublee and Aimee Curl perform. 8 p.m., Franklin Park Performing and Visual Arts Center, 36441 Blueridge View Lane, Purcellville. $22; in advance, $18. 540-338-7973.
Birding at Blue Ridge, 8 a.m., meet at the visitors center., Blue Ridge Center for Environment Stewardship, 11661 Harpers Ferry Rd., Purcellville. 540-554-2542, www.brces.org or firstname.lastname@example.org.
Leesburg winter market, sponsored by the Loudoun Valley HomeGrown Markets Association. 9 a.m.-noon, Catoctin Circle (Virginia Village Shopping Center). 540-454-8089 or www.loudounfarmersmarkets.org.
Purcellville community market, 10 a.m.- 1 p.m., It’s Bazaar, 143 N. 21st St., Purcellville. 703-967-0431 or www.loudounfarms.org.
“Conversations in History,” a presentation by Erik Buckland on “The First Rendezvous: Mosby at Mount Zion.” The lecture will be delivered on the 150th anniversary of the first gathering of Mosby’s Rangers at the site where it took place. Sponsored by the Northern Virginia Regional Park Authority and the Mosby Heritage Area Association. 11 a.m., Mount Zion Baptist Church, 40309 John S. Mosby Hwy., Aldie. $5; students, $2. 540-687-6681 or www.mosbyheritagearea.org.
Lucketts Bluegrass, music by Randy Waller and the Country Gentlemen; food sold. Music at 7 p.m.; doors open at 6 p.m. Lucketts Community Center, 42361 Lucketts Rd., Leesburg. $15. 703-771-5281 or www.luckettsbluegrass.org.
Mike Rayburn: “Guitar and Comedy,” a performer described as “Victor Borge with a guitar (and too much coffee).” 8 p.m. Saturday and 3 p.m. Sunday. Franklin Park Performing and Visual Arts Center, 36441 Blueridge View Lane, Purcellville. $15; seniors and students $12. 540-338-7973.
Friends of Thomas Balch Library meeting, a presentation by Marc Leepson on “Notes on Researching the Life of Francis Scott Key.” 2 p.m., Thomas Balch Library, 208 W. Market St., Leesburg. Free. 703-737-7195.
Toastmasters Club, NOVA Dawn Breakers. 7:30-8:30 a.m., Eggspectation restaurant, 1609 Village Market Blvd., Leesburg. 703-717-1667 or email@example.com.
Sewing and “stitch-in,” for beginners. Take sewing, knitting, needlepoint or crochet projects. Machines provided. 9-11:45 a.m., Leesburg Senior Center, 102 North St. Free. 703-737-8039.
Tai chi for adults, slow-movement exercises that aim to blend mind, spirit and body. 10-11 a.m. Mondays through March 4. Middleburg Community Center, 300 W. Washington St., Middleburg. Call for fee information. 540-687-6375.
Mah-jongg, Chinese tile game. Mondays and Thursdays at noon, Leesburg Senior Center, 102 North St. 703-737-8039.
Sterling Rotary Club meeting, 12:30 p.m., Logan’s Roadhouse, 46321 McClellan Way, Sterling. 703-401-4509.
Line dance, for people 55 and older, led by Carolyn Bledsoe. 2-3 p.m., Carver Center, 200 Willie Palmer Way, Purcellville. Nonmembers, $2. 571-258-3400.
Rotary Club of Leesburg Daybreak, 7:30 a.m., Tuscarora Mill restaurant, 203 Harrison St. SE, Leesburg. 703-622-4320 or www.leesburgdaybreak.org.
Party bridge, 1-4 p.m., Leesburg Senior Center, 102 North St. Free. 703-737-8039.
Bluegrass and folk jam, open to musicians of all skill levels. 7-8:30 p.m., Morningside House,
316 Harrison St. SE, Leesburg. Free. 571-237-2888.
Leesburg Senior Center bingo, advanced game, 9 a.m. Wednesdays; slower bingo, 12:30 p.m. Fridays, Leesburg Senior Center, 102 North St. 703-737-8039.
Middleburg duplicate bridge, open game. 12:30 p.m., Middleburg United Methodist Church, 15 W. Washington St. $5. 540-687-5093.
Preschool play drop-in, play equipment provided in the gym. Parental supervision required. 3:30-4:30 p.m., Douglass Community Center, 407 E. Market St., Leesburg. $1. 703-771-5913.
Mail: Community Events, Loudoun Living, The Washington Post,
104 Dry Mill Rd., Suite 101,
Leesburg, Va. 20175
Details: Announcements are accepted on a space-available basis from nonprofit and public organizations and must be received at least 14 days before the publication date. Include event name, dates, times, exact address, prices and a publishable contact phone number.