The music community is mourning the loss of Jack Grassel, a celebrated jazz guitarist, multi-instrumentalist, educator, composer, and author whose extraordinary career spanned more than seven decades. Grassel died unexpectedly on Wednesday, August 26, 2026, at Froedtert Hospital in Milwaukee, Wisconsin, at the age of 77.

For Grassel, music was not simply a profession but a lifelong calling. According to his family, his fascination with music began when he was a toddler, when he would reach toward piano keys while attempting to copy songs he heard on the radio. By the age of six, he had already performed his first paid concert.

His extraordinary musical abilities eventually developed into a career that saw him master seven instruments and become known particularly for his work as a guitarist. His genre-bending approach allowed him to explore different musical styles while collaborating with respected performers throughout his career.

Grassel’s influence extended well beyond the stage. In 1983, he helped design the Music Occupations Department at Milwaukee Area Technical College, creating an educational program that would influence generations of aspiring musicians. He remained with MATC for two decades before retiring from the college in 2004, although he never truly retired from music.

His career produced an impressive body of work, including 21 CDs, 70 compositions, 12 industry awards, and 23 instructional books. His dedication to teaching became one of the defining parts of his legacy, with former students going on to establish successful careers of their own.

Grassel’s professional life was closely intertwined with his personal life. In 1999, he married singer and actress Jill Jensen, with whom he shared both a marriage and a musical partnership. The couple had begun performing together in 1998, eventually appearing as a duo across the Americas and spending winters performing on Isla Mujeres in Mexico.

Jensen described their relationship as one built around an extraordinary shared love of music. Their partnership continued for decades, combining their personal connection with their creative lives.

Grassel’s final days came following a medical episode while he was driving in Caledonia on August 26. His vehicle crashed, and he was taken to hospital. Jensen was able to say goodbye to her husband before he died later that evening.

The news of his death has left a profound void for his family, students, fellow musicians, friends, and admirers. Those who knew Grassel are remembering not only his considerable musical accomplishments but also the passion and commitment that drove him to keep teaching and performing throughout his life.

He leaves behind his wife, Jill Jensen, stepdaughter Elizabeth Schram, grandchildren, brothers, extended family members, and countless friends and former students. He was also preceded in death by his two sons, Andrew Grassel and Benjamin Grassel.

Grassel’s legacy will continue through the music he created, the books he wrote, the students he taught, and the generations of musicians influenced by his example.

A celebration of his life is scheduled for October 18 in Caledonia, Wisconsin, where family, friends, and members of the music community will gather to share stories and honor the remarkable life of a man who devoted virtually every chapter of his existence to music.