How to Transpose from G to C Major on the Violin
C major and G major are relatively easy keys to play in and therefore even for one who has not transposed before, working with these scales is not overly challenging. Choose a song which is relatively simple, such as a familiar hymn or even a popular song that you are familiar with. Whether you look at the music or transpose it through writing the transposed notes on staff paper, make certain that you understand the relationship between the notes in order to get the transposition correct.
As noted above use a simple piece to transpose. For instance, Jesu, Joy of Man's Desiring by J.S. Bach is a relatively easy piece to perform. Transposing it is rather straight forward. The piece may be found in the key of G major. To change to C cimply start with the note of C. Since the violin goes down only a few notes from middle C, start your transposition with the second finger C on the A-string. This allows you to be able to play all parts of Jesu, especially when the notes get well below C. As you play or write as the case may be, remember that the notes from the original piece in G major need to be one whole step and 2 half-steps from the original G. Therefore, this means that the first measure of the piece will start out with the notes: (first measure) restCD EGF, rather than restGA BDC, starting with the G on the D string. Later in the piece, when accidentals are being used the transposition can get a little tricky. In the original G major key it proceeds as follows: DDE FsharpAGsharp GBA,(new measure) ACB CAE CDE, (new measure) FDC DBGsharp EFsharpG, etc. When transposed into a C this same passage becomes: GGA BDCsharp (new measure) DFE FDC GsharpAB (new measure) CFE FED GsharpAB, etc.
The above illustration may be a little confusing. To get help with transposing go to sites like virtual sheet music in order to get automatic transposition of a piece from one key to the next, without having to manually do it yourself. This may not work for all transpositions, but it may work for many. Additionally, talk to a friend who is a composer or arranger or who plays the piano as church or rehearsal pianists may have to transpose music to fit the key that a singer is comfortable singing in. Practice transposing with simple songs and move gradually toward more complicated pieces. Even if this is not a common thing for you to do, it helps to be familiar with the concept and practice it occassionally in order to better understand music and increase your musical skills.