When I record a streaming song some 2-3 minutes in length, the file size when recorded is about 25Mb when it should be no bigger than 2-3 Mb. How do you limit the file size for these recordings? 
Actually, it should be 25MB. You’re used to the compressed and damaged upload/internet or MP3 version. If you Export your captured Audcity show as an MP3 (requires you to add the “lame” software), you can produce the smaller files you seek.
However, if you create an MP3 in Audacity, you will double the bubbly, honky compression sound damage and you may not be happy with the product. Audacity does not edit MP3. It imports MP3s and makes whole new ones when you’re done.
You can avoid these problems by not using Audacity. You can do simple MP3 editing without the re-compression step with mp3splt or other, similar software.
Koz
Thanks Koz! I will live with it for better quality sound!