Antti Yrjö Hammarberg (14 September 1943 – 14 January 1991), professionally known as Irwin Goodman, was a Finnish rock and folk singer.
Born in Hämeenlinna, Goodman lived in Stuttgart, West Germany, in the early 1960s.
Common themes in his songs were poverty, taxes, drinking and alcoholism ("Ei tippa tapa", "Vielä yhdet", "Kieltolaki", "Homma käy", "Työmiehen lauantai", "Rentun ruusu" – approximate English translations: "One drop won't kill you", "I'll have another one", "Prohibition", "It's OK", "The workman's Saturday", "The poor man's rose") and problems with money ("Raha ratkaisee", "Kun ei rahat riitä", "Meni rahahommat pieleen", "Manu vippaa muutama markka" – approximate English translations: "Money is the solution", "When you don't have enough money", "I failed the money job", "Manu, lend me a couple of markkas").
Goodman had continuing troubles with Finnish tax authorities and had ever-worsening problems with alcohol.
Goodman died of a heart attack while on the way from Vyborg, Soviet Union, to Hamina, Finland.