There's another part to the equation, though. Your state of mind, you mood, can have a big affect on whether you feel that spark. I'm sure I read or listen to things at the wrong time for that particular piece of art. For example, I grabbed the last album from Yo La Tengo, I Am Not Afraid Of You And I Will Beat Your Ass, fairly quickly after it came out. I was in love with the song "Mr. Tough" and was expecting the whole album to sound like that. It doesn't. I thought the album was okay and stopped listening to it except for random pop-ups on shuffle. Lately, though, I've rediscovered it and dig the variety of styles through the songs. It's good stuff but stuff it took me a couple years to fully appreciate. I experienced something similar with Jarvis Cocker's debut solo album recently as well. Granted, that kind of approach works with music that exists as digital files you can keep around. But what happens when you're dealing with books?
For the past two years, I've been doing most of my reading by checking books out of the library. That means I have a finite amount of time in which to decide if that spark is there or not. As recently as a couple of years ago, I would read every book I started. I would feel I was letting a book down if I didn't. These days, though, I'll give a book anywhere from 50 to 100 pages to really grab me and if it doesn't, that's the end.
I mentioned in my Asimov's review earlier this week that Stephen Baxter's story made me want to check out the books set earlier in the story's timeline. A few days ago I checked Flood out of the library and settled in. The problem was it didn't really grab me. The characters didn't really hook me and all the water was repetitive after 50 pages and the prospect of 450 or so more was not appealing (and yes, I know the book is called Flood and I should probably have known better). So, I stopped reading my 5th book of the year (as opposed to 19 I read all the way through).
The next book up in the reading queue? Everything Matters! by Ron Currie, Jr. That spark was there from the first page, in which a baby in the womb was getting advice about not moving around so as not to wrap the umbilical cord around itself further and face dire consequences. The next 50 pages have upheld that promise and I look forward to seeing how it all turns out.
I do feel bad when I don't get that spark from a piece of art. I'm sure some of the time it's me. Of course, other times it's the work of art (don't get me started on the mess that was Greek Street #1, which I am thankful was only a buck). But when that spark happens? Magic time.