The family are at 697 Govan Rd in 1901. Andrew last born to the family it seems. Your James, aged 26 and a house painter. However, likely as Agnes in 1891, James being known to be a professional organist may have come in later years or been an additional source of income along with his trade of being a house painter. Father James Snr also showed as a house painter in 1901.
Have you followed his through to 1911 and marriage, children and death certs to see what shows for him?
Monica