[Elecraft] Transmitting audio file

[Todd Ruby]

Hello everyone 
The other day a DX station recorded my transmission and asked me if I’d like to hear how I sound. I said,”sure”, and then he replayed it on the air for me to hear. 

My question is how do I do this? My soundcard feeds the audio into my MacBook Pro, and the Pizeo app records it. 

Question how do I key the rig to transmit the recording?

tnx in advance 
73
todd
WB2ZAB