Where did the letter G come from, anyway? I know it originated as a variant of C, but I don't know what sound changes in Latin made it necessary. It would make most sense for it to have originally been /g/ and something shifted it to be /k/ in some contexts, and then later /k/ was seen as the default and /g/ a variant, which would logically lead to /g/ getting its own glyph assuming the people speaking the language could tell the difference between /k/ and /g/.
Here, I'm using /g/ to represent any of [g], [γ], [gγ], or similar sounds, as I certainly couldn't claim to know what specific voiced back-of-the-throat consonant it represented. Likewise, /k/ represents an unvoiced consonant at the same place of articulation--or possibly different but similar place.
@starkatt Are there transcripts of these? We are generally not comfortable with audio recordings but they sound interesting.
@Rosemary maybe? I haven't looked.
@Rosemary you may find this relevant! http://historyofenglishpodcast.com/2012/07/17/episode-5-centum-satem-and-the-letter-c-2/