What makes a great song?

Is it the lyrics? When they're done right, lyrics can capture a sentiment or emotion that make the listener feel like they song was written just for them. Or is it the music? Music can evoke an equally emotional response to a song; without the music to lift and transport them, after all, lyrics are just words.

Burt Bacharach is a man who knows a lot about songwriting. When he takes at the stage at Dublin's Iveagh Gardens, it is to a crowd who are fully aware that they are in the presence of musical royalty; a man who (both alone and with the late, great Hal David) has written so many songs that have become embedded in both popular culture and their own lives and memories. There are few people here tonight that don't light up when they hear the opening notes of a particular song that they grew up listening to, or perhaps fell in love to, or even lost a loved one to.

Now 91, the dapper Bacharach is still going strong and by the looks of things, he still gets plenty of enjoyment from performing. Tonight, as he takes his seat at the piano, he is backed by a full band and three singers, and they waste no time on formalities. Classy opener 'What the World Needs Now is Love' sets the tone nicely for the evening, before a medley of some of his best-known songs electrifies the sold-out crowd. From 'Walk on By' to 'I Say a Little Prayer' to 'Wishin' & Hopin', it's truly wonderful to hear these songs live – but condensed into a brief medley, they are frustratingly tantalising morsels, rather than the full four-course meals they provide on record.

Instead, Bacharach (who stands and talks to the crowd between each group of songs) focuses on devoting more time to the songs that clearly mean more to him. 'Mexican Divorce', originally sung by The Drifters in 1962, and 2003's 'Falling Out of Love', are perfectly pleasing but many patrons take the opportunity to nip to the toilet or the bar, unconcerned about missing their favourite song. It's around here that the setlist drifts dangerously close to schmaltz – and the backing singers, while all technically gifted, seem more concerned with giving it welly than injecting the songs with any sense of emotion.

Thankfully, the 'cruise ship cabaret' segment is short-lived. Order is restored with a rousing 'Make It Easy on Yourself', then Bacharach explains how the next song, 'With a Voice', was written as a reaction to Donald Trump's presidency. “If I'd written this song six months ago, it would have been even more biting,” he says, clearly irritated by 'Little Donny''s presence in world politics.

Then comes perhaps the most enjoyable part of the evening, and yet another reminder of just how all-pervasive Bacharach's touch really has been on not just music, but popular culture: the movie medley. 'The Look of Love', 'What's New Pussycat?' and 'Alfie' are all fantastic, while the ubiquitous 'Raindrops Keep Fallin' on My Head' is the biggest crowd-pleaser of all. It's followed by a gorgeous and touching rendition of 'A House is Not a Home' sung by Bacharach himself; croaky-voiced, stripped back, but with more genuine tenderness than almost anything else we've heard tonight.

An encore elicits more singalongs, this time with his twentysomething son Oliver on keyboards as Bacharach sups his first-ever pint of Guinness. 'That's What Friends Are For' is as cheesily enjoyable as it ought to be, while another full rendition of 'Raindrops' brings the set to an upbeat close as he encourages the crowd to sing along (“And if you don't know the words, just go la la la”.). It hasn't been a perfect gig - but it has been a privilege to spend the evening watching one of the greatest songwriters that music has ever known doing his thing.