Those thirty (if they actually are thirty; I can find no evidence of such a high number) are made up of numerous films in which Steiner's music from earlier films, by then part of the studios' "stock" library, was reused with a few tweaks by the composer or some of the music department's orchestrators to make it conform to the dramatic demands of new films, stories and screen-timings. I'm sure that Hugo Friedhofer had a hand in "freshening up" any number of Max's scores without Max even knowing anything about it.