Aural Resources

ABRSM Aural Trainer App (all grades, compatible with iPhone and iPad)

https://gb.abrsm.org/en/exam-support/preparation-for-exams/mock-aural-tests/

ABRSM mock aural tests, all grades (free)

http://e-musicmaestro.com/auraltests

ABRSM and Trinity tests, all grades (some free samples)

http://classic.musictheory.net/90

Ear trainer for intervals (free)

https://www.earmaster.com/downloads/free-versions.html

Ear training software for ABRSM and Trinity

https://www.earbeater.com/online-ear-training/#/

Intervals, chords and scales recognition (free)

https://tonesavvy.com/music-practice-exercises/

Exercises: intervals, chords, scales, melodic dictations (free)

https://tonedear.com

Ear training practice: intervals, scales, chords, melodic dictations (free)

https://www.bbc.co.uk/bitesize/guides/z8tsh39/revision/1

Basic harmony rules explained: chords, cadences, tonality, modes. With audio examples.

https://www.youtube.com/channel/UC8yI8P7Zi3yYTsypera-IQg/playlists

Music Matters channel with video tutorials on ABRSM aural tests presented by a professional musician, teacher and examiner. Expert tips and techniques suitable for candidates preparing for graded music exams. Also, advise on music theory tests and sight reading.

Musical periods:

https://www.classicfm.com/discover-music/periods-genres/

Musical periods explained with background info, composers, audio/video examples.

https://www.bbc.co.uk/bitesize/guides/zw3nrwx/revision/1

Brief but comprehensive description of periods in music with audio/video clips.

https://www.musicnotes.com/now/news/musical-periods-the-history-of-classical-music/

History of music in short, with audio/video clips.

https://dictionary.onmusic.org

Musical terms and signs explained with visual and audio examples.