Wow, I haven't come back here in some time, so this is a really late reply ... but I do have quite a bit more info on Matthias now.
I'll direct you to a thesis written by Rosemary Southey in 2001 that I found online, which has a great deal of information about Matthias' career: ‘COMMERCIAL MUSIC-MAKING IN EIGHTEENTH CENTURY NORTH-EAST ENGLAND: A PALE REFLECTION OF LONDON, Volume 1:
https://core.ac.uk/download/pdf/153775804.pdfThe basic details of Matthias' life are:
- He was born to Thomas Hawdon (cordwainer and Parish Clerk of All Saints Church) and Sarah Turner in 1732 in Newcastle-Upon-Tyne.
- He was baptised on 24 October 1732 at All Saints Church in Newcastle-Upon-Tyne.
- His half siblings (from Thomas' first wife, Ann Halleywell) were Thomas (b. 1717), twins Margaret and Ann (b. 1719), and Mary (b. 1720) and his full siblings were Thomas (b. 1727), Jane (b. 1729), Thomas (b. 1731), and William (b. 1734). The first two Thomases died in infancy, as did William, and Jane died in childhood. So, Matthias' siblings who survived to adulthood were Margaret (who married William Lowe), Ann (who died a spinster), Mary (who married George Douglas) and Thomas (who became a surgeon and never married).
- Matthias apprenticed under Charles Avison.
- He became the first organist of Holy Trinity Church (Hull) in 1751 after Charles Avison recommended him for the post.
- He married Mary Browne at Holy Trinity Church in Hull on 6 March 1760.
- Matthias and Mary had at least three children: Matthias (1761), Thomas (1765), and William (1767). Their son Thomas also became an organist. Their sons Matthias and William became surgeons (apprenticing under their uncle Thomas).
- Matthias became the organist of Beverley Minster (otherwise known as the Parish Church of Saint John and Saint Martin) in Beverley, an East Riding of Yorkshire in March 1769.
- Mary is thought to have died in Beverley in 1769, but needs to be confirmed.
- Matthias became the organist of St Nicholas Church in Newcastle-Upon-Tyne at the end of 1776/beginning of 1777.
- Matthias was a freemason.
- Matthias ended up bankrupt by 1781, but had recovered enough by his death to leave an estate worth 300 pounds, as per his will.
- Matthias died of "a lingering illness" in March of 1789 according to the Newcastle Advertiser published 21 March 1789. He had been unwell for some time, having withdrawn from all forms of work six months earlier.
I hope that helps!