Teaching

      - Wisconsin Lutheran College, adjunct faculty, 2003- 2007

      - Western Illinois University, guest artist, 2006, 2007

      - University of Illinois, guest artist, 2006
      - Hofner Guitar Company, clinician, 1999-2005

      - Milwaukee Area Technical College, - department chairman, coordinator of instruction,                                                        creator of the Music Occupations degree program: 1983-2004
      - Fender / Guild Guitar Company, clinician, 1999
      - National Guitar Workshop Jazz Summit, jazz faculty, 1995-1998
      - Gibson Guitar Company, clinician, 1991
      - Wisconsin Conservatory of Music, jazz degree program, faculty, 1971-1984
      - Young Audiences of Wisconsin, coordinator of jazz presentations in elementary schools, 1971-1987
      - Southern Illinois University, guest artist, 1988
      - Birch Creek Music Center, jazz faculty, 1987
      - Millikan University, guest artist, 1981
      - University of Wisconsin Whitewater, adjunct faculty, 1976
      - Cascio School of Music, instructor, 1965-1971
      - Modern Music School, instructor, 1962-1965
Writings
      - Just Jazz Guitar Magazine, columnist, 1996-2005
      - City Edition, jazz record reviewer, 1995-1998
      - Art Muscle, performance reviewer, 1995
      - Madison Music Cooperative, "Power Practicing" columnist, 1996
      - Minneapolis Jazz Newsletter, "Power Practicing"columnist, 1996
      - Guitar Player Magazine, "Master Series" columnist, 1987-1990
Education
      Private study:
      - George Van Eps, Tal Farlow, Billy Bauer, Joe Daley, Dave Holland, Don Momblow, George Pritchett,
         Emile DeCosmo, Ted Ashford, Roy Plum, Don Grzanna, Bill Ruddy and Conrad Kish, (attempted to study              with: Ed Bickert and Sam Rivers)

      Study at schools:
      - The Universities of Wisconsin: Madison, Waukesha, Milwaukee campuses (as music scholarship student)
Performances
   Jack has led his own bands of all sizes throughout the U.S. in clubs, concert arenas, and festivals for more than 30 years. He has performed as a sideman with name artists too numerous to mention, including:

      - Luciano Pavarotti, Rosemary Clooney, Nancy Wilson, John B. Williams, Roy McCurdy, Frankie Laine,             Richie Crabtree, Maureen McGovern, Cab Calloway, Jay Leno, Bob Hope, Louie Bellson, Vic Damone,          Tom Jones, Al Martino, Joel Grey, Mel Rhyne, Bobby Rydell, The Drifters, The Crystals, Lainie Kazan,          David Benoit, Ira Sullivan, Ed Thigpen, Howard Levy, Debbie Reynolds, Lana Cantrell,                                       The Barnum and Bailey Circus, Holiday on Ice, Bob Newhart, Buddy Montgomery, Doc Severinson,             Myron Floren and the Stars of the Lawrence Welk Show tour, Margaret Whiting, Rose Marie, Eartha Kitt,     Helen O'Connell, John Gary, Chad Mitchell, Henny Youngman, Martha Ray, Jim Kerhin, Buster Williams,     Roger Williams, Percy Faith, Paul Wertico, Rita Moreno, Morton Gould, Lucas Foss, McCoy Tyner, June Valli, Anna Marie Albergetti, Barry Williams, John Raitt, Jerry Vale, Bobby Vinton, Jimmie Rodgers, Trini Lopez,    Donna Fargo, Art Hoyle, Tal Farlow, Barry Harris, Mamie Van Doren, Mark Eagan, Gary Willis, Carol Channing, Rufus Ried, Donald O'Connor, Slide Hampton, John Scofield, Ritchie Cole, Stu Katz, Marlena Shaw,       Marlene Rosenburg, Jerry Van Dyke, Fabian, Richard Hayman, Marcus Roberts, Bobby Vinton, Phyllis Newman, Sandler and Young, Sergio Franchi, Greg Federico, Michael Feinstein, Dane Richeson, Skitch Henderson, Tommy Leonetti, Gloria Loring, Jimmy Webb, Theodore Bikel, Adam Levy, Stanley Jordan, Harold Jones,     Ernie Adams, Dennis Day, Jackie Allen, Nancy Ames, Phil Ford, Mimi Hines, Hans Sturm, Jeff Pietrangelo,     Greg Koch, Berkeley Fudge, Muriel Anderson, Tim Reynolds, Kirk Tatnall, Steve Peplin, Leigh Cowan,           Bill Schaefgen, The Bar "O" Ranch, Bill Martin, Sam Belton, Steve Nelson-Raney, Randy Knackert and 45rpm.
Endorsements
     Jack uses whatever picks, guitars, cables, strings, amps and speakers he feels like using to present his daily musical vision.  His tone comes from his fingers.  His music comes from his brain, shaped by life experience.

However, to make his music realized in the real world for others to hear, he uses, may use or has used:

-  Raezor's Edge speaker cabinets:  The Jack Grassel model JG-10,  2006 - present

-  George L cables, 1994 - present

-  Surf picks, 2003 - present

-  Moshay picks, 1967 - present
-  Hofner guitars.1999-2005
-  Jack has used Walter Woods amplifiers, 1975 - present 
-  Fender & Guild guitars,1998
-  Gibson guitars, 1991

- Jack sometimes buys equipment at Lincoln Music, Uncle Bob's Music, Schmitt Music, Gary's Music,                           Paramount Guitars and JHale Music.

- Jack gets his guitar serviced by luthiers Jim Eanelli, and Ron Jones.

- The official Jack Grassel gig-mobile is an old Oldsmobile which is kept running by Cory at McFarland's Motors in Racine, Wisconsin.

- Jack's fingernails are maintained by Tom at T & C NAILS, N81 W15074 Appleton Avenue in Menomenee Falls,           Wisconsin:  phone 262 502 1737