The City of Birmingham Symphony Orchestra has been given one of the largest gifts in its history.
The orchestra has not revealed the man's name but says he was "very special to us" and started supporting them in memory of his wife.
The Lichfield gentleman left them a legacy of £800,000, a spokesman said.
The cash is a "significant contribution" to the £15m to £20m it needs over the next eight years and for its centenary in 2020.
The orchestra, which is based at Birmingham's Symphony Hall, said the money was left by a "frequent CBSO concert-goer" and "supporting member".
Chief Executive Stephen Maddock OBE, said: "I am always touched and humbled when I learn that someone has chosen to remember us in this way: in doing so they ensure we can continue to offer musical inspiration for generations to come."
Mr Maddock added money raised from the private sector helps to maintain and build on their "world-class standards".
"Without such support every aspect of our work would be diminished beyond recognition."