If I hadn't already transcribed her chord progressions to the number system, I don't think it would have turned out as well as it did. Using the number system in place of the chord name itself will greatly benefit any one using your transcription to play that song in a different key than what you have transcribed it in. Roman numerials are generally used in text written applications to not cause confusion, but when hand writting I usually just use regular numbers. Take this 50's style progression for example. This progression can be quickly transposed to any key without having to rethink the particular scale.
Advanced chords are also identifiable under the numbering system.
And chords outside the written scale are identified by representing the true chord by a flat sign. I hope that this information will be of use to you and help you in the future. Hello Cowpies, I had a lot of responce from the lesson I submitted concerning the numbering system and have submitted a little more to help clear up some questions that have been asked. The song below was sent to me from Gene Graham asking that I use it as an example showing the corresponding numbering over the listed chord. Also, I have included a chart to show the correct numbering used for each chord in relation to its key.