In addition to these celebrity clients, C.A.K. Entertainment also works with corporate brands including Barrett-Jackson, The World's Greatest Car Collector Auctions. Under the guidance of C.A.K. Entertainment, Barrett-Jackson began airing their live auctions on The Discovery Channel in January 2015, bringing their viewership to a broader audience within the United States as well as launching them internationally.

Charles has served as a board member for Six Flags Entertainment Corporation since 2010 and as a board member for Las Vegas Sands Corporation since 2011. Up until September 2011, Charles served six years as the Executive Chairman and Principal Executive Officer of Martha Stewart Living Omnimedia and seven years as a director of the company. Koppelman played a central role in guiding the company through a period of challenges and into an era of diversification and expansion. He forged new business relationships that renewed and strengthened MSLO's dominant position in consumer and lifestyle media and merchandising including:

• MSLO's acquisition of Chef Emeril Lagasse's media and merchandising business.
• An agreement with Federated Stores to develop a line of Martha Stewart Collection home merchandise (from textiles to housewares and holiday items) exclusively for Macy's stores nationwide.
• A partnership with The Home Depot to offer an exclusive brand of Martha Stewart Living brand home-improvement products.
• A partnership to create a significant block of programming, including "The Martha Stewart Show,” to air on Hallmark Channel.
• A contract with Sirius Satellite Radio to establish the Martha Stewart Living Radio channel.

From 2000 to 2004, Koppelman served as Chairman of the Board of Steve Madden Ltd. He was primarily responsible for the successful management of the shoe company during Madden's absence.

Koppelman's previous business experience was largely in the entertainment industry, where over a period of 40 years he was known as one of the industry's most insightful and successful leaders. His career in the entertainment industry dates back to the early 1960s. He has held key management roles at CBS Records, Columbia Records, EMI Music Publishing and EMI Music Group North America and has established and led a series of highly successful independent music publishing and record production companies with various business partners.

In 1991, Koppelman earned an award for his achievements outside of music—the Humanitarian of the Year Award from the T. J. Martell Foundation for Leukemia, Cancer, and AIDS Research.

Koppelman has been a board member of the T.J. Martell Foundation, the Rock and Roll Hall of Fame, NY Presbyterian Hospital and Hofstra University. He also served on the arts board at Tufts University and is the benefactor of the school's Koppelman Art Gallery. He also is a trustee of North Shore Hospital, a member of the Dean's Council at Hofstra Law School, a member of the board of governors of New York Hospital, and a member of the board of trustees at Hofstra University, where the Koppelman Law Library resides. In 1992, Koppelman was honored along with former Soviet President Mikhail Gorbachev by Yeshiva University.

Created world's largest publishing company

In 1975, Koppelman formed The Entertainment Company with Martin Bandier and Samuel LeFrak. The company independently administered and promoted song catalogs and signed artists directly to their company to place them with a record company. By 1981, the company had its own staff of producers and 20 in-house songwriters. Koppelman cultivated top musicians like Barbra Streisand, Dolly Parton, Diana Ross, the Four Tops and Cher.

In 1984, Koppelman and Bandier purchased the Combine Music catalog of 25,000 country songs. They continued to pursue new artists during this time of expansion, signing then-unknown artists such as Tracy Chapman. Koppelman and Bandier took on a new partner in 1986—financier and carpet and furniture magnate, Stephen C. Swid - as part of a plan to purchase the interests of CBS Songs, Inc.

The new partnership, named SBK Entertainment World, Inc., bought the 250,000 titles owned by CBS Songs for $125 million, the highest price ever paid for a music publishing catalog. SBK developed into the largest independent music publisher in the world and played a major role in the success of artists like Michael Bolton, Robbie Robertson, New Kids on the Block, Ice House, Al B. Sure!, and Eric B. & Rakim.

An influential Force in Music

In 1989, SBK Entertainment World, Inc. was sold to EMI Music for $300 million. As part of the deal, Koppelman and Bandier formed a partnership with EMI Music Worldwide to create their own record label, SBK Records. EMI put up $15 million in seed money, while Koppelman and Bandier invested $10 million. In addition, Koppelman took the positions of Chairman and CEO of the new label and Chairman of EMI Music Publishing. Bandier received the posts of President and Chief Operating Officer of SBK Records and Vice-Chairman of EMI Music Publishing.

EMI Music Publishing won many industry awards during Koppelman's tenure, including publisher of the year honors bestowed by both the American Society of Composers, Authors and Publishers (ASCAP) and Broadcast Music, Incorporated (BMI). In 1990 Koppelman received the Abe Olman Publishers Award through the Songwriters Hall of Fame. Just one year after inception, SBK Records received its first platinum album with Technotronic's Pump Up the Jam. SBK Records went on to sign successful new artists like Jesus Jones, Wilson Phillips, and Vanilla Ice.