Trance is a form of music best characterized by quarter note drum patterns, and 16th/32nd note rhythm synthesizer patterns. It has a meter of 4/4, with a quarter note bassdrum acting as metronome, and quarter note high-hat hits on upbeats. This unwavering drum mechanism may be constantly tweaked with for effect, with the Attack, Decay, Sustain, Release ( ADSR ) all given liberal treatment. The tempo is generally around 130-158 beats per minute (bpm).

The arrangement consists mostly of a repeating 32nd note sequencing arpeggio , and a bass section of whole notes usually drifting through the aeolian or natural minor scale. Harmonic structure is typically minimalist, with often no more than 2-4 chords. Iterations of the i-iv-v progression (A minor, D minor, and E minor, for example) lend a dark feel by eschewing major chords entirely. Additional rhythm sections are added and subtracted every 16 measures (sometimes 8, and sometimes 32) to add weight and anticipation to the composition. The bass chord will usually change every 4 measures.

There is a lead synth, and it will be a simple minor scale melody of 8th notes, looping every 4 measures (some have 2, some have 8. Some even have 16). Trance is produced with keyboards , computerized synthesizers , drum machines , and music sequencer software connected via MIDI . The average trance song has a polyphony of 8. The most busy will have 16.

Some sub-genre classifications of trance include:

• Acid trance : An early '90's style. Characterized by the use of a Roland TB-303 bass machine as the lead synth.
  • Artists: Hardfloor , Art of Trance , Eternal Basement
• Anthem trance : Style of trance that emerged in the wake of progressive trance in the late 90's. Characterized by extended chord progression in all elements (lead synth, bass chords, treble chords), extended breakdowns, and relegation of arpeggiation to the background while bringing wash effects to the fore.
  • Artists: Vincent De Moor , Ronski Speed , Tiësto , System F , Super8 , Ayla , Paul Van Dyk , Armin Van Buuren
• Classic trance : Original form of trance music, said to have originated in the very early 90's. Characterized by less percussion than techno, more melody, arpeggiated melody, and repetitive melodic chords/arpeggios.
  • Artists: Resistance D , Progressive Attack , Arpeggiators , Union Jack , Dance 2 Trance , Jam and Spoon
• Euro-Trance : Euro-Trance is a hybrid of Techno and Eurodance music incorporating Hardstyle bass drums and trance elements. The trance synths at times sound like techno hoovers with trancey effects and strings backing it up. The vocals are often pitched up for the most part, but sometimes they can be heard as in normal pitch range. This is often confused as Vocal Trance because of its use of vocals. The lyrical content is usually pretty simple, containing an introduction to the song with usually no or little drums, and often includes renderings of classic Happy Hardcore anthems or melodies.
  • Artists: DJ Trancemaster , Groove Coverage , Jan Wayne , Starsplash , Rob Mayth , Special D and DJ Volume .
• Goa trance : A complexly melodic form of trance named for Goa, India, and originating in the early 90's. Often uses the Raga .
  • Artists: Psygone , mfg , S.U.N. Project , Man With No Name , Astral Projection , Juno Reactor
• Hard Trance : Aggressive sounding, Originating in Frankfurt, includes influences from hardcore and hard house.
  • Artists: DJ Scot Project , DJ Wag , Yoji Biomehanika , Cosmic Gate , Hennes & Cold , DuMonde
• Hardstyle : Closely related to Nu Style Gabber and hard trance. Its sound is usually characterized by a mix of gabber and hardcore like kick/bass sounds, trance like synth stabs and sweeps and miscellaneous samples. However, Hardstyle usually has a lot slower BPM (between 140 and 150).
  • Artists: Blutonium Boy , Lady Dana , DJ Pavo .
• Progressive trance : Style of trance that originated in the early-mid 90's. Differentiated from the then "regular" Trance by bass chord changes that gave the repeating lead synth a feeling of "progression"
  • Artists: BT , Cosmic Baby , Art of Trance , Sasha , John Digweed
• Psychedelic trance : (better known as Psytrance , ambiguously synonymous with Goa trance, less melodic more abstract and futuristic)
  • Artists: Shiva Chandra , Etnica , Infected Mushroom , Astrix , Phacelift , Total Eclipse
• Vocal trance : Broad term referring to trance with a full set of lyrics, which may or may not be any of the above genres. Oftentimes an artist will borrow a singer's talents as opposed to the singer herself (vocalists are typically female), or sample from/remix more traditional pop music. Note that there is some debate as to where the divide lies between Vocal Trance and Pop or Eurodance.
  • Artists: 4 Strings, Lange, Ian van Dahl , Oceanlab, Fragma, Paradise, Lost Witness, Armin Van Buuren