I am trying to learn jazz standarts from the real book and for example when I play "autumn leaves" or "black orhpeus" with guitar from the real book it sounds simpler than original recordings of Paul Desmond. What causes this and how can I practice in a way that is more similar to their music?
The Real Book is meant to give you the basic ingredients for these standards, they are not full scores or transcriptions. I would hope that at least the head is correct but sometimes it isn't. The chords may or may not come close to those on the recording and much of unique elements of the recording are completely missing, like intros etc.
You can learn the tune and make it your own from the Real Book (and that's the intent), but you will never get the authentic feel of the original from it. That is why they list the recordings in the Real Book. You are supposed to find them, and listen. Your ear is the best way to learn.
Real and fake books are skeletons of classic tunes. They're the bare bones - containing minimal information. The basic tune (lead) and the harmonies (chords), sometimes with alternative chords shown. They're really not meant to be any more, any less. They're enough for musicians to have in front of them to play, straight off, any of those tunes.
Because it's mostly jazz, even a simple rendition may deviate from what's written - it's what jazz does - so expecting anything in the Real book to be a faithful copy of any recording is folly. And if one only plays the tune, bare, or the chords, with no melody, well, it's hardly going to sound like a trio or quartet track.
Listen to ten different recordings of, say, Autumn leaves, and you'll recognise the melody (at least first time round!), but then you'll hear ten different - often very different - 'translations' of the piece. All probably initially gleaned from a Real book.
Plus - they're going to sound rather different unless you use the same instrumentation as on tha recording, and maybe - even the same players!
A Real Book chart is often based on the most popular version of the tune, not necessarily the original. For example, Autumn Leaves and Black Orpheus are from the Sinatra versions.
And, as stated in other answers, these charts are intended to show the conceptual framework of a tune, rather than capture nuance of a particular version.
As the other answers point out the Real Book is just a collection of lead sheets.
You must be just starting out with jazz so you should look at both:
- Fake books and lead sheets, and get some books or lessons about how to play from a fake book. There are lots of lessons for that.
- Jazz transcriptions, which is when someone writes down in notation a recorded jazz improvisation.
- Original published sources. Depending on the song you can get the original music many standard songs come from Broadway musicals.
My personal peeve was with rhythm changes and the song I Got Rhythm. There literally is no one definitive version of rhythm changes. There are endless examples of the changes and lead sheet versions. I finally got a copy of the Gershwin music from a published copy of the musical Girl Crazy. But, even that was surely not the notation pages used by the orchestra for the original production. It was just a piano reduction. You can also find various piano solos which are probably the work of various editors/arrangers and not necessarily a transcription of anything Gershwin played himself!
Eventually you realize this kind of music - jazz and pop music - is not about a definitive score. I suspect many famous tunes started as some combination of composer's notebooks, band charts, etc. used to make a first recording and those sources are not published. Then some sheet music version was published for people to play at home, either to promote the tune or to meet demand for a popular tune. Other musicians perform and record the tune. In jazz the first fake book was developed and people wrote lead sheets that sketched a general outline of songs.
There is no "urtext" like in classical music. You need to look for the resource that fits your purpose...
how can I practice in a way that is more similar to their music?
- get some resources about how to play from a fake book, you don't simply play the lead sheet exactly as written
- look for transcriptions of specific performances you like, the traditional jazz way is to do it by ear, "quote" parts of their playing or emulate it in a general sense
One final thought. You tagged your question with guitar, but compared the fake book to Paul Desmond recordings. You will probably have an easier time learning how to play guitar from a fake book if you compare to recordings or jazz guitarists.