I am a Notorious 'Noodler' , but NOT with Unaccompanied songs - I am fully aware that a lot if singers vary the metre to suit the song (AND their feeling) , and with acconmpanied song , I DO like to sort out the arrangement , but QUIETLY unless I get a Nod to join in .
Last thing I would ever do is impose MY idea of how a song should be performed on another performer .
Sessions and Singarounds in UK are normally two totally different things - No One at a 'Session' should be performing intricate arrangements of songs in C# - Sessions are for joining in !