Maybe it is more difficult to find the definition than to decide practically what to consider oral tradition and what not. Lena Bourne Fish had a sort of family songbook, some of her sources where printed, no doubt, but I'd put her in the oral tradition group. Me, I live in Abruzzo, Italy. If a drifting collector would catch me humming The Outlandish Knight, the version in Frank Kidson, Traditional Tunes, 1891, noted from the singing of Charles Lolley in Leeds, I wouldn't say that Lady Isabel and the Elf Knight is stil alive and well in the oral tradition ... in Abruzzo. Of some of the Child Ballads we've had recordings in the XXth century from seamen, farmers, Travellers, chainmakers, etc. Of other ballads, no. Some where thought to be estinguished in the oral tradition, such as Child #3, until the recordings of Nellie MacGregor,Bella Higgins and Duncan McPhee. I agree that "oral tradition" is a concept to handle with care, but it means something and is useful.