A "Pro Sound" 61-key beginner keyboard is a lightweight, all-in-one electronic instrument. It covers 5 octaves (C2 to C7), making it a highly practical and affordable choice for new players.Common core specifications typically include the following:Core HardwareNumber of Keys: 61 standard/full-size piano-style keys (unweighted or semi-weighted).Polyphony: Usually 32 to 64 notes (the number of notes that can sound simultaneously).Speakers: Built-in dual stereo speakers (typically 5W to 10W each).Power Source: AC adapter (included) or 4 to 6 AA batteries for portability.Sounds & RhythmsTones/Voices: Ranging from 100 to 650+ built-in sounds (pianos, strings, synths, drums).Rhythms/Styles: 100 to 255+ auto-accompaniment backing tracks.Demo Songs: 10 to 50+ pre-loaded songs for listening and practice.Learning & Performance FeaturesTeaching.