I recently began taking singing lessons twice a week. I am a low tenor, with my highest note being G# above middle C.
I advised my coach that I want to sing as high as possible, in the post-hardcore style, similar to the likes of Anthony Green (Saosin) or Tyson Stevens (Scary Kids Scaring Kids). He told me that these vocalists reached incredibly high notes (D# above high C and even higher) using a Mixed voice, instead of pure Chest voice.
I have had two lessons with him for 30 minutes, focusing on bridging the 'cracking' between my chest and head voice, but I cannot seem to find my 'mixed voice' register. When performing scales for practicing mixed voice, I reach a stage where my voice is no longer capable to hit a higher note, and I crack into falsetto in an un-satisfying way.
With daily practice, how long would it normally take a novice vocalist to understand and master the mixed voice technique?