The march thats played usually when the bride comes down the aisle of the
church is the bridal chorus from Lohegrin composed by Wagner.  The march
thats typically played when the couple leave the altar and walk down the
aisle is Mendelssohn's from the Incidental Music from "A Midsummer's Night
Dream".

Both versions are readily available on any CD that has wedding music as a
theme.  Hope this helps you.

Kim Patrick Clow <[log in to unmask]>