Can we rerecord an original piece of music from your library, ie: add lyrics, change tempo etc, without being penalized?

Yes and no. You can't re-record a piece of our library yourself. This is one of the reasons why we don't make the stems of our songs available, as explained in our article Do I have access to stems?

However, it is possible for us to create unique versions, by re-recording ourselves in our studios. Our sound engineers will be able to bring the extra, unique touch you need to your project. We invite you to contact us so that we can review your request and assist you. All the contact details are in our article How can I contact you?