“Good evening. Welcome to Difficult Listening Hour. The spot on your dial for that relentless and impenetrable sound of difficult music.” This is how Laurie Anderson introduces one of the many spine-chilling tracks on her extraordinary United States Live, a set that was released on six records in 1984 and is now available on four CDs for a princely sum. I can’t think of any live set as long and as engaging as this: each of the tracks on it – some sung, some spoken in an array of different voices – offers the comforts of difficult listening Anderson jokingly extols in that opening.

There is a fairly pervasive assumption – often unspoken – that popular music should be easy: easy to categorise, easy to find and easy to listen to. Turn on just about any local radio station, and the music jumps out of the speakers at you, as if it wants to make the distance between the song and your mind as short as possible.

The trouble is that so much of the pleasure you get from listening to music requires time and energy. It is dependent on close attention, on a certain distance you have to travel towards the music. Anderson herself describes this relationship on her Bright Red album as a long thin line, a “tightrope made of sound.”

Any one of my favourite albums - Anderson’s, say, or anything by The Velvet Underground – have had me sitting back at some stage to make room for something strange and new. Sometimes these have been hit records; sometimes my body has moved to their rhythms, sometimes there was no rhythm to speak of. But always I have felt myself meeting the music halfway rather than passively consuming it. All these records refused to fade into background noise no matter how much I turned the volume button up or down. Whereas so much “radio-friendly” music today might jump out at you from the speakers, but background noise is exactly what it fades into at whatever volume it is played.

The strangeness of Anderson’s sonic vision might be a bridge too far for some, though her timing alone ought to be enough to win over even the hardest of hearts. For a very different example of challenging music, listen to Chuck Berry’s gorgeous Memphis, Tennessee from 1963. In it someone is asking long distance information to help him get in touch with a party named Marie. The song has all the visceral, apparently uncomplicated energy of early rock ‘n’ roll at its best; on the surface nothing could be further from Anderson’s avant-garde sophistication. But there’s something about the song that forces you to pay close attention. It’s partly that Berry is such a great storyteller - we learn towards the end that Marie is only six years old. But there is something else, something to do with Berry’s phrasing and the way he speeds up or slows down his delivery of the lines. Behind the joke on us there is somethingslightly unhinged in his voice: when he pleads with long distance at the end of the song, there is a moment when you aren’t sure that his anguish isn’t real.

And so, once again, we don’t know where we are. We’re back on that invisible tightrope made of sound.