Lamech in Cain's descendants has 3 sons, each whom is described with a particular skill (ESV 4:20-22):
Adah bore Jabal; he was the father of those who dwell in tents and have livestock.
His brother's name was Jubal; he was the father of all those who play the lyre and pipe.
Zillah also bore Tubal-cain; he was the forger of all instruments of bronze and iron...
What is interesting is the first two are called "the father of those who..." The third has a skill but is not "the father of those..."
Does this mean if you play the instruments or dwell in tents you are genetically/ancestrally derived from one of these two guys? In what sense were Jabal and Jubal the "fathers" of those with particular skills? And what is the significance of distinction with the third son?