First thing: DID YOU CUT OFF THE MIDDLE LEG, AND ARE YOU USING 2N3904 NPN TRANSISTORS?
The super simple oscillator def is finicky. You are basically exploiting a behavior of transistors such that they are breaking down (reverse avalanche). Save yourself some headache and make sure you only really try this with some transistors that have been known to “work” (technically break) at 9v.
Get yourself a bunch of 2N3904 NPN transistors. As was stated before, there isnt any guarantee that even the first 5 you test will work.
If you are curious about how the reverse avalanche stuff works, and some voltages needed for various transistors this site has proved useful:
http://www.kerrywong.com/2014/03/19/bjt-in-reverse-avalanche-mode/
According to kerry wong’s blog post, the BC337 and SS9018 require less voltages which is appealing for the 9v battery option.
btw, you just put the youtube URL and it will embed on this forum.