Here's a list of the songs in FFVII AC soundtrack and the FFVII themes played during them.

DISC 1
* Opening - Taken from FFVII's track Opening ~ Bombing Mission.
* The Promised Land - A new theme.
* Beyond the Wasteland - Has parts from Sephiroth's theme, "Those Chosen by the Planet".
* Sign - It reminds me a bit about FFVII's song "Who Am I?", but I don't think it uses any themes from VII.
* Tifa's Theme - Taken from FFVII Piano Collections. Uses Tifa's Theme (well doh ).
* For the Reunion - A new track.
* Those Who Fight - Taken from FFVII Piano Collections. Uses FFVII's normal battle theme.
* Water - Reminds me a lot about other FFs (FFX?), but I think it's a new theme.
* Materia - A new track.
* Black Water - A new track.
* Aerith's Theme - Taken from FFVII Piano Collections. Uses Aeris' Theme from FFVII.
* Battle in the Forgotten City - A new track. It reminds me a bit about FFVIII, though.
* Violator - The beginning sounds like the Shinra Corporation's theme.
* The Great Northern Cave - Uses FFVII's track "The Great Northern Cave", which is the second world map theme. It plays on the world map (FFVII spoiler)after the Meteor has been summoned. It might also play during your first visit to the Northern Crater, after Gaea's Cliff.

DISC 2
* Divinity I - A new theme.
* Those Who Fight - Harder to recognise, but it's a rock remix of FFVII's normal battle theme.
* Those Who Fight Further - Again, harder to recognise, but it's a rock remix of FFVII's boss battle theme.
* Divinity II - A new theme. It has a moment where Aeris' theme plays.
* Encounter - A new track.
* The Chase of Highway - Uses the Turks' Theme.
* Savior - A new track.
* J-E-N-O-V-A - A remix of FFVII's song J-E-N-O-V-A. It sounds a lot like the version performed by the Black Mages, but it's shorter and the arrangement is somewhat different.
* Advent: One-Winged Angel - A remake of FFVII's song, One-Winged Angel.
* (Possible AC spoiler)Cloud Smiles - It reminds me about FFX and FFX-2's ending themes. It's a new track, though the ending sounds like it has references to Aeris' theme.
* End Credits - It uses the Main Theme of Final Fantasy VII, Aeris' theme and the main FF (Prologue) theme.
* CALLING - A "new" song, not made by Square Enix.