It's a fair trade-off. If the complexities of the man require that he can't narcissistically dwell on the masterpieces of the past and still produce new work, then it's a fair trade-off. If the physical realities of a mind made of meat limit the memory space devoted to tuneful ditties of yesterday so that creative endeavors of tomorrow may flourish, then it's a fair trade-off. If the cost is a disappointingly poor performance from time-to-time for whatever reason, and the pay-off is work such as "Liars," "The Individualist" and "A Cappella," then it's a fair trade-off.
I didn't experience the frustration of Melbourne Wed. night, but I have been to 30+ shows over the past 20 years and have witnessed my share of forgotten lyrics, broken strings, technical problems, on-stage confusion, set lists that don't seem to change, as well as entire shows that are hard to get through (Allentown, Pa in Oct. 2001, for instance), and personally, I'm ok with all this. If the flubs and screw-ups are part of the totality of Todd, if the flying by-the-seat-of-his-pants on-stage vibe is an integral part of the balance of his strengths and weakness, and if the result of this balance, of this totality are the sublime and exquisite songs he's been giving us, then groovy! I'll take the broken strings and the screw-ups gladly, I'll happily listen to him butcher "Song of the Viking" yet again, I'll sit through "Hello, It's Me" for what feels like the millionth time with a smile on my face because I know that when the next album comes out, even if it's another 10 years down the line, it will be utterly superb. It's absolutely a fair trade-off. It's more than fair.
And another thing.... Todd has made it pretty clear that the songs from way back ("Hello, It's Me," for instance) lost relevance for him long ago (and thank God they did, because if the works of 30+ years ago were still indicative of his mental/emotional/spiritual state, there's no way we'd be getting such goodies as the ones on "Liars"), yet he still includes them in his set. Rather than focusing on what went wrong with the performance of these songs and viewing the missteps as indicative of a lack of respect for his audience, I feel that the fact that he includes these songs at all - songs that have little meaning for him any longer - shows how much respect he does have for his audience and our desire to walk down memory lane.
Just my two cents - of course, I'm just another onionhead.