OK, so I was able to find the info:

This Is Your Life

Theme (1952 - 1961): "This Is Your Life"; aka: "Life Theme";

Alexander Laszlo and his Orchestra performed the theme he composed on both NBC and CBS radio versions. When the series went on television this theme was also used.

By the time "This Is Your Life" moved to television, Laszlo was quite busy scoring several series including "My Little Margie", "Waterfront", "Beulah", and others, So Von Dexter and his Orchestra performed the music on the TV series (This includes all the incidental music, remember, this was live TV).

Composers: Music by Alexander Laszlo (ASCAP) [professional name of Sandor ("San") Totis] with lyric added by L. Wolfe Gilbert (ASCAP) [It is unknown exactly what this refers to but might only be some sort of voiced-over introduction to the show. It is unlikely to actually be lyrics.].

Original Publisher: Guild Publications of California (ASCAP), of Hollywood, CA.

1998 Publisher: The Regents of the University of California, of Berkeley, CA on behalf of Alexander Publications, Inc. (ASCAP)

Published Copyright Date: Nov. 1, 1949; EP 42 427.

Recordings: LP: "This Is Your Life" (1958) Von Dexter and his Orchestra, Imperial LP-9051.


Hope this helps.
Blackcatter