Sēo clafer (Niwenglisc: piano, Italisc: pianoforte) is a cǣġbord ġesundmacian þæt crǣften sund hƿonne sēo cǣġe earun þringede. Mǣsten clafer hæfþ a rǣw æf 88 blæc and hwītcǣġe: 52 hwītcǣġe for sēo nōtas æf sēo C strang stæger (C, D, E, F, G, A, and B) and 36 sċeortere and þynnere blæccǣġe rǣrdon ābufan sēo hwītcǣġe and settan furþor bæc, for sċearpan and flæden. Þæs mǣndon þæt sēo claferfort cann plæġan 88 different piċa (or "notās"), spannung a æfstande æf a bit ofer seofon ǣctāfes. Sēo blæccǣġe earun for sēo "wyrden", hwīc earun nēdede to pleoġan in eall tƿelf cǣġe.
Þǣre earun tƿā main floccas æf clafer: sēo mǣreclafer and sēo upprihtclafer. Sēo mǣreclafer offrode bætanere sund and more precise cǣġ control, maecnung hit sēo preferred choice hƿonne space and budget allow. Sēo mǣreclafer is eac geseald gerǣdnyssa in stōwum ðǣr cræftigum geacnod wordt clafercrǣfteneres. Sēo upprihtclafer is māre gewuneliclice brūcod bēon for ðȳ lǣssan lengðe and lǣgum coste.
Hƿonne a cǣġ is þringede dūne, sēo tyhtanede strenġas insīde earun stricon bī feltþeahton wuduene hamors. Sēo swengan earun sendon þurh a brycg to a sundbord þæt ymbrisianes sēo sund bī gefeohtung sēo gleohǣdigstyrn to sēo lyft. Hƿonne sēo cǣġ is lǣtanede, a dampfere stoppode sēo strenġas sweng, ending sēo sund. Mǣsten nōtas hæfþ þrī strenġas, forbī for sēo bass, hwīc āfæstbūrend fram ān to tƿā. Notes can be sustained hƿonne sēo cǣġe earun lǣtanede bī sēo use æf fōtbarren at sēo base æf sēo ġesundmacian, hwīc hold sēo dampferen af æf sēo strenġas. Sēo sustain fōtbarre allows pianists to pleġan wegan, swylce handa sciftende fram grundleornes to trēowræstem, hwīlum healde æt accorde, ġetācnunge ġestandende, swilce melōdiās and earpegoras oferhāliġe.
On mǣreclafer, sēo frama and sēo strengas sīeþ ūpāsende, mid sē strengas ǣrwǣges būfan sē clāfestrecc. Sē ġewinn bīþ beneoþan sē strengas and brūcaþ grǣgewīse swā his ġewinn ongeān hweorfeþ tō ǣlīþendlīcum stæðe. Mǣre ġeclæncas ġestreon ūt tō ōðþæt is ōð 1.5–3 m (4 ft 11 in – 9 ft 10 in) lang. Summ of sē langas hæfþ ġifon mā or lǣssa ǣðelcundum nama, sē æfter sīþðes and stōwe tō stōwe þæt is brādu.
Ūpprihtclaferes, ġenemned ġēondæc clæncas, sīeþ cōmpaċtra for ðām uprēm weorcframum and strengum. Sē cēaplic weorcfram ōþre clæncas wæs ġeferod on Lunden, Englaland in 1826 fram Roberht Ƿornum, and ūferan mēodu becōman þā mǣran mēodu for ānsetlīc brūcung. Ūferan clæncas nāman lǣs rūm ðonne mǣre clæncas, and swā swā hȳ wǣron betera mēasu for ānsetlīcum hūsūm for ānsetlīcum sȳnnesāum and ānsetlīcum þeáwum. Sē hameras hweorfaþ beheġde, and ġeondfeorþaþ tō hyra restendan ġestæde tō andan fruman, sē ġehēþolade synt tō fordwīnenne. Ūferan clæncas mid ūnǣnliċum hēah rēom and lǣnga strengum wǣron sumtīdġes beċȳmede swā ūferan mǣran clæncas, ac sē nama is lǣsƿordig. Summe scriftwriteras dǣlað nūtīde clæncas æfter hyra hēaðe and æfter þām tōbygan geðancum ðe bēoþ neadliċe tō onfealdenne sēo hēað. Ūferan clæncas eardlīce sīeþ lǣs cōstliċe ðonne mǣre clæncas. Ūferan clæncas sīeþ wīdlīċe brūcade on cirican, folcesetlum, scoolum, sāngstōwum and ǣlāfedum sāngprōgramum swā hyra hreġelian and frīġian forboden, and hī sīeþ lǣswierþe mǣrƿeorcum for inhaman geƿritum.