Classic rock guitarist and former UFO member Paul "Tonka" Chapman sadly passed away on Tuesday, June 9 -- his 66th birthday. As Classic Rock points out, one of his children confirmed the news on his Facebook, writing, "It is with a heavy heart writing this, today is my dads 66th birthday. He passed away earlier this afternoon. He was a brilliant, energetic, loving and most carefree person and the First man I ever loved. Everyone he came in contact with loved him. no ADORED him. will keep everyone posted on his celebration of life. I appreciate everyone's thoughts and prayers as his family grieves and processes everything at this time. I love you Dad. So much." No cause of death has been given at this time.

UFO also wrote, "We send our deepest sympathy to the family and friends of Paul Tonka Chapman, who died yesterday, on his 66th birthday. Paul's son broke the tragic news on Paul's Facebook page yesterday evening. R.I.P. Tonka."

Early on in Chapman's career, he played in the Irish blues rock band Skid Row (not to be confused with American heavy metal band of the same name), which was fronted by Thin Lizzy vocalist Phil Lynott. Later on, he joined UFO as a live guitarist between 1974 and 1975, before forming Lone Star who existed from 1975 to 1978. After Lone Star's demise, Chapman rejoined UFO in 1978 and remained with them as a full-time member until 1983, playing on four of their albums: 1980's No Place To Run, 1981's The Wild, The Willing And The Innocent, 1982's Mechanix, and 1983's Making Contact.

Chapman was involved in other projects over the years, including UFO bassist Pete Way's band Waysted, a lesser known band called Ghost, and more.

Former Motorhead guitarist Phil Campbell was among the people to pay tribute to Chapman, writing, "Just woke up to sad news of Paul Chapman passing. He was my main influence on guitar for many years and a brilliant bloke. Thoughts are with his family. RIP Tonka"

Rest in peace, Paul. You'll be missed.

Watch Paul perform with UFO in 1980: