While there are many tools to convert audio CD’s from one format to another, here’s another way to convert audio CDs to MP3 in Ubuntu.
Insert the audio CD you want to convert in the CD drive
Copy the tracks on the audio CD to wav files using:
cdparanoia -B <enter>
To convert to MP3, use a tool called Sound Converter. If you have not installed it on your system, you can do so using:
sudo apt-get install soundconverter <enter>
or alternatively, use the Software Center to find it and install it.