With iTunes you can purchase songs from the iTunes store and from Amazon and you can also download songs from CD's. This means you have more options than with Spotify. With Spotify you are mostly stuck with what Spotify has in their library.
You only need to spend money for songs you can't get from CD's. Most customers usually end up spending less than $50 on music.
iTunes will give you the best performance during your wedding and also the best song selection. You just need to put more time into it opposed to Spotify
TIP: CD’s can be obtained from your public library for free and you can easily download them into your iTunes.
The BEST feature about iTunes is you can edit songs. You can edit out a weird intro or shorten a song by cutting out the end. By doing this you save some awkward transitions between songs. Especially if you are Just Pressing Play and letting the music roll.
You can also edit the length of the songs down in order to fit more songs into your playlist. Most songs have their appeal after 3 minutes and guests are ready to move on. And with the crossfade turned on you can hardly notice the song was edited down.
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